--- contrib/tzdata/CONTRIBUTING.orig
+++ contrib/tzdata/CONTRIBUTING
@@ -5,23 +5,29 @@
 warning, the data entries do not cover all of civil time before
 1970, and undoubtedly errors remain in the code and data.  Feel
 free to fill gaps or fix mistakes, and please email improvements
-to tz@iana.org for use in the future.
+to tz@iana.org for use in the future.  In your email, please give
+reliable sources that reviewers can check.
 
+-----
+
+Developers can contribute technical changes to the source code and
+data as follows.
+
 To email small changes, please run a POSIX shell command like
 'diff -u old/europe new/europe >myfix.patch', and attach
 myfix.patch to the email.
 
-For more-elaborate changes, please read the Theory file and browse
-the mailing list archives <http://mm.icann.org/pipermail/tz/> for
-examples of patches that tend to work well.  Ideally, additions to
+For more-elaborate changes, please read the theory.html file and browse
+the mailing list archives <https://mm.icann.org/pipermail/tz/> for
+examples of patches that tend to work well.  Additions to
 data should contain commentary citing reliable sources as
-justification.
+justification.  Citations should use https: URLs if available.
 
 Please submit changes against either the latest release in
-<ftp://ftp.iana.org/tz/> or the master branch of the experimental
-Git repository.  If you use Git the following workflow may be helpful:
+<https://www.iana.org/time-zones> or the master branch of the development
+repository.  If you use Git the following workflow may be helpful:
 
-  * Copy the experimental repository.
+  * Copy the development repository.
 
       git clone https://github.com/eggert/tz.git
       cd tz
--- contrib/tzdata/LICENSE.orig
+++ contrib/tzdata/LICENSE
@@ -1,4 +1,5 @@
-With a few exceptions, all files in the tz code and data (including
-this one) are in the public domain.  The exceptions are date.c,
-newstrftime.3, and strftime.c, which contain material derived from BSD
-and which use the BSD 3-clause license.
+Unless specified below, all files in the tz code and data (including
+this LICENSE file) are in the public domain.
+
+If the files date.c, newstrftime.3, and strftime.c are present, they
+contain material derived from BSD and use the BSD 3-clause license.
--- contrib/tzdata/Makefile.orig
+++ contrib/tzdata/Makefile
@@ -49,6 +49,7 @@
 # "Compiled" time zone information is placed in the "TZDIR" directory
 # (and subdirectories).
 # Use an absolute path name for TZDIR unless you're just testing the software.
+# TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty.
 
 TZDIR_BASENAME=	zoneinfo
 TZDIR=		$(TOPDIR)/etc/$(TZDIR_BASENAME)
@@ -72,11 +73,11 @@
 
 LIBDIR=		$(TOPDIR)/lib
 
-# If you always want time values interpreted as "seconds since the epoch
-# (not counting leap seconds)", use
+# If you want only POSIX time, with time values interpreted as
+# seconds since the epoch (not counting leap seconds), use
 #	REDO=		posix_only
-# below.  If you always want right time values interpreted as "seconds since
-# the epoch" (counting leap seconds)", use
+# below.  If you want only "right" time, with values interpreted
+# as seconds since the epoch (counting leap seconds), use
 #	REDO=		right_only
 # below.  If you want both sets of data available, with leap seconds not
 # counted normally, use
@@ -85,10 +86,31 @@
 # normally, use
 #	REDO=		right_posix
 # below.  POSIX mandates that leap seconds not be counted; for compatibility
-# with it, use "posix_only" or "posix_right".
+# with it, use "posix_only" or "posix_right".  Use POSIX time on systems with
+# leap smearing; this can work better than unsmeared "right" time with
+# applications that are not leap second aware, and is closer to unsmeared
+# "right" time than unsmeared POSIX time is (e.g., 0.5 vs 1.0 s max error).
 
 REDO=		posix_right
 
+# To install data in text form that has all the information of the binary data,
+# (optionally incorporating leap second information), use
+#	TZDATA_TEXT=	tzdata.zi leapseconds
+# To install text data without leap second information (e.g., because
+# REDO='posix_only'), use
+#	TZDATA_TEXT=	tzdata.zi
+# To avoid installing text data, use
+#	TZDATA_TEXT=
+
+TZDATA_TEXT=	leapseconds tzdata.zi
+
+# For backward-compatibility links for old zone names, use
+#	BACKWARD=	backward pacificnew
+# To omit these links, use
+#	BACKWARD=
+
+BACKWARD=	backward pacificnew
+
 # If you want out-of-scope and often-wrong data from the file 'backzone', use
 #	PACKRATDATA=	backzone
 # To omit this data, use
@@ -96,6 +118,11 @@
 
 PACKRATDATA=
 
+# The name of a locale using the UTF-8 encoding, used during self-tests.
+# The tests are skipped if the name does not appear to work on this system.
+
+UTF8_LOCALE=	en_US.utf8
+
 # Since "." may not be in PATH...
 
 YEARISTYPE=	./yearistype
@@ -103,50 +130,53 @@
 # Non-default libraries needed to link.
 LDLIBS=
 
-# Add the following to the end of the "CFLAGS=" line as needed.
+# Add the following to the end of the "CFLAGS=" line as needed to override
+# defaults specified in the source code.  "-DFOO" is equivalent to "-DFOO=1".
 #  -DBIG_BANG=-9999999LL if the Big Bang occurred at time -9999999 (see zic.c)
+#  -DDEPRECATE_TWO_DIGIT_YEARS for optional runtime warnings about strftime
+#	formats that generate only the last two digits of year numbers
+#  -DEPOCH_LOCAL if the 'time' function returns local time not UT
+#  -DEPOCH_OFFSET=N if the 'time' function returns a value N greater
+#	than what POSIX specifies, assuming local time is UT.
+#	For example, N is 252460800 on AmigaOS.
 #  -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r
+#  -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ'
 #  -DHAVE_DIRECT_H if mkdir needs <direct.h> (MS-Windows)
-#  -DHAVE_DOS_FILE_NAMES if file names have drive specifiers etc. (MS-DOS)
-#  -DHAVE_GETTEXT=1 if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris)
-#  -DHAVE_INCOMPATIBLE_CTIME_R=1 if your system's time.h declares
+#  -DHAVE_GENERIC=0 if _Generic does not work
+#  -DHAVE_GETTEXT if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris)
+#  -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares
 #	ctime_r and asctime_r incompatibly with the POSIX standard
 #	(Solaris when _POSIX_PTHREAD_SEMANTICS is not defined).
-#  -DHAVE_INTTYPES_H=1 if you have a pre-C99 compiler with "inttypes.h"
+#  -DHAVE_INTTYPES_H if you have a non-C99 compiler with <inttypes.h>
 #  -DHAVE_LINK=0 if your system lacks a link function
 #  -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function
 #  -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz
-#	This defaults to 1 if a working localtime_rz seems to be available.
 #	localtime_rz can make zdump significantly faster, but is nonstandard.
 #  -DHAVE_POSIX_DECLS=0 if your system's include files do not declare
 #	functions like 'link' or variables like 'tzname' required by POSIX
-#  -DHAVE_STDINT_H=1 if you have a pre-C99 compiler with "stdint.h"
-#  -DHAVE_STRFTIME_L=1 if <time.h> declares locale_t and strftime_l
-#	This defaults to 0 if _POSIX_VERSION < 200809, 1 otherwise.
+#  -DHAVE_SNPRINTF=0 if your system lacks the snprintf function
+#  -DHAVE_STDBOOL_H if you have a non-C99 compiler with <stdbool.h>
+#  -DHAVE_STDINT_H if you have a non-C99 compiler with <stdint.h>
+#  -DHAVE_STRFTIME_L if <time.h> declares locale_t and strftime_l
 #  -DHAVE_STRDUP=0 if your system lacks the strdup function
 #  -DHAVE_SYMLINK=0 if your system lacks the symlink function
-#  -DHAVE_SYS_STAT_H=0 if your compiler lacks a "sys/stat.h"
-#  -DHAVE_SYS_WAIT_H=0 if your compiler lacks a "sys/wait.h"
+#  -DHAVE_SYS_STAT_H=0 if your compiler lacks a <sys/stat.h>
+#  -DHAVE_SYS_WAIT_H=0 if your compiler lacks a <sys/wait.h>
 #  -DHAVE_TZSET=0 if your system lacks a tzset function
-#  -DHAVE_UNISTD_H=0 if your compiler lacks a "unistd.h" (Microsoft C++ 7?)
-#  -DEPOCH_LOCAL=1 if the 'time' function returns local time not UT
-#  -DEPOCH_OFFSET=N if the 'time' function returns a value N greater
-#	than what POSIX specifies, assuming local time is UT.
-#	For example, N is 252460800 on AmigaOS.
-#  -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU=1
-#	if you do not want run time warnings about formats that may cause
-#	year 2000 grief
-#  -Dssize_t=long on ancient hosts that lack ssize_t
-#  -DTHREAD_SAFE=1 to make localtime.c thread-safe, as POSIX requires;
+#  -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>
+#  -Dlocale_t=XXX if your system uses XXX instead of locale_t
+#  -Dssize_t=long on hosts like MS-Windows that lack ssize_t
+#  -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires;
 #	not needed by the main-program tz code, which is single-threaded.
 #	Append other compiler flags as needed, e.g., -pthread on GNU/Linux.
 #  -Dtime_tz=\"T\" to use T as the time_t type, rather than the system time_t
+#	This is intended for internal use only; it mangles external names.
 #  -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz"
 #  -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory;
 #	the default is system-supplied, typically "/usr/lib/locale"
 #  -DTZDEFRULESTRING=\",date/time,date/time\" to default to the specified
 #	DST transitions if the time zone files cannot be accessed
-#  -DUNINIT_TRAP=1 if reading uninitialized storage can cause problems
+#  -DUNINIT_TRAP if reading uninitialized storage can cause problems
 #	other than simply getting garbage data
 #  -DUSE_LTZ=0 to build zdump with the system time zone library
 #	Also set TZDOBJS=zdump.o and CHECK_TIME_T_ALTERNATIVES= below.
@@ -154,27 +184,28 @@
 #	(or some other number) to set the maximum time zone abbreviation length
 #	that zic will accept without a warning (the default is 6)
 #  $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking
-GCC_DEBUG_FLAGS = -Dlint -g3 -O3 -fno-common -fstrict-aliasing \
-	-Wall -Wextra \
-	-Wbad-function-cast -Wcast-align -Wdate-time \
-	-Wdeclaration-after-statement \
-	-Wdouble-promotion \
-	-Wformat=2 -Winit-self -Wjump-misses-init \
-	-Wlogical-op -Wmissing-prototypes -Wnested-externs \
-	-Wold-style-definition -Woverlength-strings -Wpointer-arith \
-	-Wshadow -Wstrict-prototypes -Wsuggest-attribute=const \
-	-Wsuggest-attribute=format -Wsuggest-attribute=noreturn \
-	-Wsuggest-attribute=pure -Wtrampolines \
-	-Wunused -Wwrite-strings \
-	-Wno-address -Wno-format-nonliteral -Wno-sign-compare \
-	-Wno-type-limits -Wno-unused-parameter
+# Select instrumentation via "make GCC_INSTRUMENT='whatever'".
+GCC_INSTRUMENT = \
+  -fsanitize=undefined -fsanitize-address-use-after-scope \
+  -fsanitize-undefined-trap-on-error -fstack-protector
+GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
+  $(GCC_INSTRUMENT) \
+  -Wall -Wextra \
+  -Walloc-size-larger-than=100000 -Warray-bounds=2 \
+  -Wbad-function-cast -Wcast-align -Wdate-time \
+  -Wdeclaration-after-statement -Wdouble-promotion \
+  -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \
+  -Winit-self -Wjump-misses-init -Wlogical-op \
+  -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \
+  -Wold-style-definition -Woverlength-strings -Wpointer-arith \
+  -Wshadow -Wshift-overflow=2 -Wstrict-prototypes -Wstringop-overflow=5 \
+  -Wsuggest-attribute=const -Wsuggest-attribute=format \
+  -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \
+  -Wtrampolines -Wundef -Wuninitialized -Wunused \
+  -Wvariadic-macros -Wvla -Wwrite-strings \
+  -Wno-address -Wno-format-nonliteral -Wno-sign-compare \
+  -Wno-type-limits -Wno-unused-parameter
 #
-# If you want to use System V compatibility code, add
-#	-DUSG_COMPAT
-# to the end of the "CFLAGS=" line.  This arrange for "timezone" and "daylight"
-# variables to be kept up-to-date by the time conversion functions.  Neither
-# "timezone" nor "daylight" is described in X3J11's work.
-#
 # If your system has a "GMT offset" field in its "struct tm"s
 # (or if you decide to add such a field in your system's "time.h" file),
 # add the name to a define such as
@@ -186,6 +217,31 @@
 # and define NO_TM_ZONE to suppress any guessing.  These two fields are not
 # required by POSIX, but are widely available on GNU/Linux and BSD systems.
 #
+# The next batch of options control support for external variables
+# exported by tzcode.  In practice these variables are less useful
+# than TM_GMTOFF and TM_ZONE.  However, most of them are standardized.
+# #
+# # To omit or support the external variable "tzname", add one of:
+# #	-DHAVE_TZNAME=0
+# #	-DHAVE_TZNAME=1
+# # to the "CFLAGS=" line.  "tzname" is required by POSIX 1988 and later.
+# # If not defined, the code attempts to guess HAVE_TZNAME from other macros.
+# # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause
+# # crashes when combined with some platforms' standard libraries,
+# # presumably due to memory allocation issues.
+# #
+# # To omit or support the external variables "timezone" and "daylight", add
+# #	-DUSG_COMPAT=0
+# #	-DUSG_COMPAT=1
+# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by
+# # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later.
+# # If not defined, the code attempts to guess USG_COMPAT from other macros.
+# #
+# # To support the external variable "altzone", add
+# #	-DALTZONE
+# # to the end of the "CFLAGS=" line; although "altzone" appeared in
+# # System V Release 3.1 it has not been standardized.
+#
 # If you want functions that were inspired by early versions of X3J11's work,
 # add
 #	-DSTD_INSPIRED
@@ -223,11 +279,6 @@
 #	-DALL_STATE
 # to the end of the "CFLAGS=" line.  Storage is obtained by calling malloc.
 #
-# If you want an "altzone" variable (a la System V Release 3.1), add
-#	-DALTZONE
-# to the end of the "CFLAGS=" line.
-# This variable is not described in X3J11's work.
-#
 # NIST-PCTS:151-2, Version 1.4, (1993-12-03) is a test suite put
 # out by the National Institute of Standards and Technology
 # which claims to test C and Posix conformance.  If you want to pass PCTS, add
@@ -237,8 +288,8 @@
 # If you want strict compliance with XPG4 as of 1994-04-09, add
 #	-DXPG4_1994_04_09
 # to the end of the "CFLAGS=" line.  This causes "strftime" to always return
-# 53 as a week number (rather than 52 or 53) for those days in January that
-# before the first Monday in January when a "%V" format is used and January 1
+# 53 as a week number (rather than 52 or 53) for January days before
+# January's first Monday when a "%V" format is used and January 1
 # falls on a Friday, Saturday, or Sunday.
 
 CFLAGS=
@@ -262,7 +313,7 @@
 
 # How to use zic to install tz binary files.
 
-ZIC_INSTALL=	$(ZIC) -y $(YEARISTYPE) -d $(DESTDIR)$(TZDIR) $(LEAPSECONDS)
+ZIC_INSTALL=	$(ZIC) -d $(DESTDIR)$(TZDIR) $(LEAPSECONDS)
 
 # The name of a Posix-compliant 'awk' on your system.
 AWK=		awk
@@ -286,6 +337,7 @@
 # The name, arguments and environment of a program to validate your web pages.
 # See <http://openjade.sourceforge.net/doc/> for a validator, and
 # <https://validator.w3.org/source/> for a validation library.
+# Set VALIDATE=':' if you do not have such a program.
 VALIDATE = nsgmls
 VALIDATE_FLAGS = -s -B -wall -wno-unused-param
 VALIDATE_ENV = \
@@ -352,7 +404,7 @@
 RANLIB=		:
 
 TZCOBJS=	zic.o
-TZDOBJS=	zdump.o localtime.o asctime.o
+TZDOBJS=	zdump.o localtime.o asctime.o strftime.o
 DATEOBJS=	date.o localtime.o strftime.o asctime.o
 LIBSRCS=	localtime.c asctime.c difftime.c
 LIBOBJS=	localtime.o asctime.o difftime.o
@@ -367,20 +419,22 @@
 			time2posix.3.txt \
 			tzfile.5.txt tzselect.8.txt zic.8.txt zdump.8.txt \
 			date.1.txt
-COMMON=		CONTRIBUTING LICENSE Makefile NEWS README Theory version
+COMMON=		calendars CONTRIBUTING LICENSE Makefile \
+			NEWS README theory.html version
 WEB_PAGES=	tz-art.htm tz-how-to.html tz-link.htm
 DOCS=		$(MANS) date.1 $(MANTXTS) $(WEB_PAGES)
 PRIMARY_YDATA=	africa antarctica asia australasia \
 		europe northamerica southamerica
-YDATA=		$(PRIMARY_YDATA) pacificnew etcetera backward
+YDATA=		$(PRIMARY_YDATA) etcetera $(BACKWARD)
 NDATA=		systemv factory
 TDATA=		$(YDATA) $(NDATA)
 ZONETABLES=	zone1970.tab zone.tab
-TABDATA=	iso3166.tab leapseconds $(ZONETABLES)
+TABDATA=	iso3166.tab $(TZDATA_TEXT) $(ZONETABLES)
 LEAP_DEPS=	leapseconds.awk leap-seconds.list
-DATA=		$(YDATA) $(NDATA) backzone $(TABDATA) \
-			leap-seconds.list yearistype.sh
-AWK_SCRIPTS=	checklinks.awk checktab.awk leapseconds.awk
+TZDATA_ZI_DEPS=	zishrink.awk $(TDATA) $(PACKRATDATA)
+DATA=		$(YDATA) $(NDATA) backzone iso3166.tab leap-seconds.list \
+			leapseconds yearistype.sh $(ZONETABLES)
+AWK_SCRIPTS=	checklinks.awk checktab.awk leapseconds.awk zishrink.awk
 MISC=		$(AWK_SCRIPTS) zoneinfo2tdf.pl
 TZS_YEAR=	2050
 TZS=		to$(TZS_YEAR).tzs
@@ -387,13 +441,13 @@
 TZS_NEW=	to$(TZS_YEAR)new.tzs
 TZS_DEPS=	$(PRIMARY_YDATA) asctime.c localtime.c \
 			private.h tzfile.h zdump.c zic.c
-ENCHILADA=	$(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) $(TZS)
+ENCHILADA=	$(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) $(TZS) tzdata.zi
 
 # Consult these files when deciding whether to rebuild the 'version' file.
 # This list is not the same as the output of 'git ls-files', since
 # .gitignore is not distributed.
 VERSION_DEPS= \
-		CONTRIBUTING LICENSE Makefile NEWS README Theory \
+		calendars CONTRIBUTING LICENSE Makefile NEWS README \
 		africa antarctica asctime.c asia australasia \
 		backward backzone \
 		checklinks.awk checktab.awk \
@@ -402,7 +456,7 @@
 		leap-seconds.list leapseconds.awk localtime.c \
 		newctime.3 newstrftime.3 newtzset.3 northamerica \
 		pacificnew private.h \
-		southamerica strftime.c systemv \
+		southamerica strftime.c systemv theory.html \
 		time2posix.3 tz-art.htm tz-how-to.html tz-link.htm \
 		tzfile.5 tzfile.h tzselect.8 tzselect.ksh \
 		workman.sh yearistype.sh \
@@ -424,7 +478,7 @@
 			$(DESTDIR)$(MANDIR)/man3 $(DESTDIR)$(MANDIR)/man5 \
 			$(DESTDIR)$(MANDIR)/man8
 		$(ZIC_INSTALL) -l $(LOCALTIME) -p $(POSIXRULES)
-		cp -f iso3166.tab $(ZONETABLES) $(DESTDIR)$(TZDIR)/.
+		cp -f $(TABDATA) $(DESTDIR)$(TZDIR)/.
 		cp tzselect zic zdump $(DESTDIR)$(ETCDIR)/.
 		cp libtz.a $(DESTDIR)$(LIBDIR)/.
 		$(RANLIB) $(DESTDIR)$(LIBDIR)/libtz.a
@@ -445,6 +499,11 @@
 		printf '%s\n' "$$V" >$@.out
 		mv $@.out $@
 
+# This file can be tailored by setting BACKWARD, PACKRATDATA, etc.
+tzdata.zi:	$(TZDATA_ZI_DEPS)
+		LC_ALL=C $(AWK) -f zishrink.awk $(TDATA) $(PACKRATDATA) >$@.out
+		mv $@.out $@
+
 version.h:	version
 		VERSION=`cat version` && printf '%s\n' \
 		  'static char const PKGVERSION[]="($(PACKAGE)) ";' \
@@ -470,6 +529,7 @@
 # Arguments to pass to submakes of install_data.
 # They can be overridden by later submake arguments.
 INSTALLARGS = \
+ BACKWARD=$(BACKWARD) \
  DESTDIR=$(DESTDIR) \
  LEAPSECONDS='$(LEAPSECONDS)' \
  PACKRATDATA='$(PACKRATDATA)' \
@@ -478,10 +538,8 @@
  ZIC='$(ZIC)'
 
 # 'make install_data' installs one set of tz binary files.
-# It can be tailored by setting LEAPSECONDS, PACKRATDATA, etc.
-install_data:	zic leapseconds yearistype $(PACKRATDATA) $(TDATA)
-		$(ZIC_INSTALL) $(TDATA)
-		$(AWK) '/^Rule/' $(TDATA) | $(ZIC_INSTALL) - $(PACKRATDATA)
+install_data:	zic leapseconds yearistype tzdata.zi
+		$(ZIC_INSTALL) tzdata.zi
 
 posix_only:
 		$(MAKE) $(INSTALLARGS) LEAPSECONDS= install_data
@@ -518,14 +576,14 @@
 
 zones:		$(REDO)
 
-$(TZS_NEW):	$(TDATA) zdump zic
+$(TZS_NEW):	tzdata.zi zdump zic
 		mkdir -p tzs.dir
-		$(zic) -d tzs.dir $(TDATA)
-		$(AWK) '/^Link/{print $$1 "\t" $$2 "\t" $$3}' \
-		   $(TDATA) | LC_ALL=C sort >$@.out
+		$(zic) -d tzs.dir tzdata.zi
+		$(AWK) '/^L/{print "Link\t" $$2 "\t" $$3}' \
+		   tzdata.zi | LC_ALL=C sort >$@.out
 		wd=`pwd` && \
 		zones=`$(AWK) -v wd="$$wd" \
-				'/^Zone/{print wd "/tzs.dir/" $$2}' $(TDATA) \
+				'/^Z/{print wd "/tzs.dir/" $$2}' tzdata.zi \
 			 | LC_ALL=C sort` && \
 		./zdump -i -c $(TZS_YEAR) $$zones >>$@.out
 		sed 's,^TZ=".*tzs\.dir/,TZ=",' $@.out >$@.sed.out
@@ -542,7 +600,8 @@
 		cp $(TZS_NEW) $(TZS)
 
 libtz.a:	$(LIBOBJS)
-		$(AR) ru $@ $(LIBOBJS)
+		rm -f $@
+		$(AR) -rc $@ $(LIBOBJS)
 		$(RANLIB) $@
 
 date:		$(DATEOBJS)
@@ -560,18 +619,24 @@
 		chmod +x $@.out
 		mv $@.out $@
 
-check:		check_character_set check_white_space check_links check_sorted \
-		  check_tables check_tzs check_web
+check:		check_character_set check_white_space check_links \
+		  check_name_lengths check_sorted \
+		  check_tables check_web check_zishrink check_tzs
 
 check_character_set: $(ENCHILADA)
-		LC_ALL=en_US.utf8 && export LC_ALL && \
+	test ! '$(UTF8_LOCALE)' || \
+	! printf 'A\304\200B\n' | \
+	  LC_ALL='$(UTF8_LOCALE)' grep -q '^A.B$$' >/dev/null 2>&1 || { \
+		LC_ALL='$(UTF8_LOCALE)' && export LC_ALL && \
 		sharp='#' && \
 		! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \
 			$(MISC) $(SOURCES) $(WEB_PAGES) \
-			CONTRIBUTING LICENSE Makefile README version && \
+			CONTRIBUTING LICENSE Makefile README \
+			version tzdata.zi && \
 		! grep -Env $(SAFE_SHARP_LINE) $(TDATA) backzone \
 			leapseconds yearistype.sh zone.tab && \
-		! grep -Env $(OK_LINE) $(ENCHILADA)
+		! grep -Env $(OK_LINE) $(ENCHILADA); \
+	}
 
 check_white_space: $(ENCHILADA)
 		patfmt=' \t|[\f\r\v]' && pat=`printf "$$patfmt\\n"` && \
@@ -578,6 +643,13 @@
 		! grep -En "$$pat" $(ENCHILADA)
 		! grep -n '[[:space:]]$$' $(ENCHILADA)
 
+PRECEDES_FILE_NAME = ^(Zone|Link[[:space:]]+[^[:space:]]+)[[:space:]]+
+FILE_NAME_COMPONENT_TOO_LONG = \
+  $(PRECEDES_FILE_NAME)[^[:space:]]*[^/[:space:]]{15}
+
+check_name_lengths: $(TDATA) backzone
+		! grep -En '$(FILE_NAME_COMPONENT_TOO_LONG)' $(TDATA) backzone
+
 CHECK_CC_LIST = { n = split($$1,a,/,/); for (i=2; i<=n; i++) print a[1], a[i]; }
 
 check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab
@@ -592,6 +664,7 @@
 
 check_links:	checklinks.awk $(TDATA)
 		$(AWK) -f checklinks.awk $(TDATA)
+		$(AWK) -f checklinks.awk tzdata.zi
 
 check_tables:	checktab.awk $(PRIMARY_YDATA) $(ZONETABLES)
 		for tab in $(ZONETABLES); do \
@@ -602,14 +675,32 @@
 check_tzs:	$(TZS) $(TZS_NEW)
 		diff -u $(TZS) $(TZS_NEW)
 
-check_web:	$(WEB_PAGES)
-		$(VALIDATE_ENV) $(VALIDATE) $(VALIDATE_FLAGS) $(WEB_PAGES)
+# This checks only the HTML 4.01 strict page.
+# To check the the other pages, use <https://validator.w3.org/>.
+check_web:	tz-how-to.html
+		$(VALIDATE_ENV) $(VALIDATE) $(VALIDATE_FLAGS) tz-how-to.html
 
+# Check that tzdata.zi generates the same binary data that its sources do.
+check_zishrink: tzdata.zi zic leapseconds $(PACKRATDATA) $(TDATA)
+		for type in posix right; do \
+		  mkdir -p time_t.dir/$$type time_t.dir/$$type-shrunk && \
+		  case $$type in \
+		    right) leap='-L leapseconds';; \
+	            *) leap=;; \
+		  esac && \
+		  $(ZIC) $$leap -d time_t.dir/$$type $(TDATA) && \
+		  $(AWK) '/^Rule/' $(TDATA) | \
+		    $(ZIC) $$leap -d time_t.dir/$$type - $(PACKRATDATA) && \
+		  $(ZIC) $$leap -d time_t.dir/$$type-shrunk tzdata.zi && \
+		  diff -r time_t.dir/$$type time_t.dir/$$type-shrunk || exit; \
+		done
+		rm -fr time_t.dir
+
 clean_misc:
 		rm -f core *.o *.out \
 		  date tzselect version.h zdump zic yearistype libtz.a
 clean:		clean_misc
-		rm -fr *.dir tzdb-*/ $(TZS_NEW)
+		rm -fr *.dir tzdata.zi tzdb-*/ $(TZS_NEW)
 
 maintainer-clean: clean
 		@echo 'This command is intended for maintainers to use; it'
@@ -663,6 +754,7 @@
 		  touch -cmr `ls -t $$file workman.sh | sed 1q` $$file.txt || \
 		    exit; \
 		done
+		touch -cmr `ls -t $(TZDATA_ZI_DEPS) | sed 1q` tzdata.zi
 		touch -cmr `ls -t $(TZS_DEPS) | sed 1q` $(TZS)
 		touch -cmr `ls -t $(VERSION_DEPS) | sed 1q` version
 		touch $@
@@ -674,7 +766,7 @@
 		$(MAKE) maintainer-clean
 		$(MAKE) "CFLAGS=$(GCC_DEBUG_FLAGS)" ALL
 		mkdir -p public.dir
-		for i in $(TDATA) ; do \
+		for i in $(TDATA) tzdata.zi; do \
 		  $(zic) -v -d public.dir $$i 2>&1 || exit; \
 		done
 		$(zic) -v -d public.dir $(TDATA)
@@ -768,8 +860,8 @@
 			$(MAKE) clean ; \
 		done
 
-zonenames:	$(TDATA)
-		@$(AWK) '/^Zone/ { print $$2 } /^Link/ { print $$3 }' $(TDATA)
+zonenames:	tzdata.zi
+		@$(AWK) '/^Z/ { print $$2 } /^L/ { print $$3 }' tzdata.zi
 
 asctime.o:	private.h tzfile.h
 date.o:		private.h
@@ -785,6 +877,7 @@
 .PHONY: check check_character_set check_links
 .PHONY: check_public check_sorted check_tables
 .PHONY: check_time_t_alternatives check_tzs check_web check_white_space
+.PHONY: check_zishrink
 .PHONY: clean clean_misc force_tzs
 .PHONY: install install_data maintainer-clean names
 .PHONY: posix_only posix_packrat posix_right
--- contrib/tzdata/NEWS.orig
+++ contrib/tzdata/NEWS
@@ -1,5 +1,344 @@
 News for the tz database
 
+Release 2017c - 2017-10-20 14:49:34 -0700
+
+  Briefly:
+  Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
+  Fiji ends DST 2018-01-14, not 2018-01-21.
+  Namibia switches from +01/+02 to +02 on 2018-04-01.
+  Sudan switches from +03 to +02 on 2017-11-01.
+  Tonga likely switches from +13/+14 to +13 on 2017-11-05.
+  Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
+  A new file tzdata.zi now holds a small text copy of all data.
+  The zic input format has been regularized slightly.
+
+  Changes to future time stamps
+
+    Northern Cyprus has decided to resume EU rules starting
+    2017-10-29, thus reinstituting winter time.
+
+    Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
+    predicted.  (Thanks to Dominic Fok.)  Adjust future predictions
+    accordingly.
+
+    Namibia will switch from +01 with DST to +02 all year on
+    2017-09-03 at 02:00.  This affects UT offsets starting 2018-04-01
+    at 02:00.  (Thanks to Steffen Thorsen.)
+
+    Sudan will switch from +03 to +02 on 2017-11-01.  (Thanks to Ahmed
+    Atyya and Yahia Abdalla.)  South Sudan is not switching, so
+    Africa/Juba is no longer a link to Africa/Khartoum.
+
+    Tonga has likely ended its experiment with DST, and will not
+    adjust its clocks on 2017-11-05.  Although Tonga has not announced
+    whether it will continue to observe DST, the IATA is assuming that
+    it will not.  (Thanks to David Wade.)
+
+    Turks & Caicos will switch from -04 all year to -05 with US DST on
+    2018-03-11 at 03:00.  This affects UT offsets starting 2018-11-04
+    at 02:00.  (Thanks to Steffen Thorsen.)
+
+  Changes to past time stamps
+
+    Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
+    (Thanks to Arthur David Olson.)
+
+    Detroit did not observe DST in 1967.
+
+    Use railway time for Asia/Kolkata before 1941, by switching to
+    Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
+    1906.  Also, treat 1941-2's +0630 as DST, like 1942-5.
+
+    Europe/Dublin's 1946 and 1947 fallback transitions occurred at
+    02:00 standard time, not 02:00 DST.  (Thanks to Michael Deckers.)
+
+    Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
+    American time in 1892, not 1879.  (Thanks to Michael Deckers.)
+
+    Adjust the 1867 transition in Alaska to better reflect the
+    historical record, by changing it to occur on 1867-10-18 at 15:30
+    Sitka time rather than at the start of 1867-10-17 local time.
+    Although strictly speaking this is accurate only for Sitka,
+    the rest of Alaska's blanks need to be filled in somehow.
+
+    Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
+    (Thanks to Michael Deckers.)
+
+    Add 7 s to the UT offset in Asia/Yangon before 1920.
+
+  Changes to zone names
+
+    Remove Canada/East-Saskatchewan from the 'backward' file, as it
+    exceeded the 14-character limit and was an unused misnomer anyway.
+
+  Changes to build procedure
+
+    To support applications that prefer to read time zone data in text
+    form, two zic input files tzdata.zi and leapseconds are now
+    installed by default.  The commands 'zic tzdata.zi' and 'zic -L
+    leapseconds tzdata.zi' can reproduce the tzdata binary files
+    without and with leap seconds, respectively.  To prevent these two
+    new files from being installed, use 'make TZDATA_TEXT=', and to
+    suppress leap seconds from the tzdata text installation, use 'make
+    TZDATA_TEXT=tzdata.zi'.
+
+    'make BACKWARD=' now suppresses backward-compatibility names
+    like 'US/Pacific' that are defined in the 'backward' and
+    'pacificnew' files.
+
+    'make check' now works on systems that lack a UTF-8 locale,
+    or that lack the nsgmls program.  Set UTF8_LOCALE to configure
+    the name of a UTF-8 locale, if you have one.
+
+    Y2K runtime checks are no longer enabled by default.  Add
+    -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
+    adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
+    to disable them.  (New name suggested by Brian Inglis.)
+
+    The build procedure for zdump now works on AIX 7.1.
+    (Problem reported by Kees Dekker.)
+
+  Changes to code
+
+    zic and the reference runtime now reject multiple leap seconds
+    within 28 days of each other, or leap seconds before the Epoch.
+    As a result, support for double leap seconds, which was
+    obsolescent and undocumented, has been removed.  Double leap
+    seconds were an error in the C89 standard; they have never existed
+    in civil timekeeping.  (Thanks to Robert Elz and Bradley White for
+    noticing glitches in the code that uncovered this problem.)
+
+    zic now warns about use of the obsolescent and undocumented -y
+    option, and about use of the obsolescent TYPE field of Rule lines.
+
+    zic now allows unambiguous abbreviations like "Sa" and "Su" for
+    weekdays; formerly it rejected them due to a bug.  Conversely, zic
+    no longer considers non-prefixes to be abbreviations; for example,
+    it no longer accepts "lF" as an abbreviation for "lastFriday".
+    Also, zic warns about the undocumented usage with a "last-"
+    prefix, e.g., "last-Fri".
+
+    Similarly, zic now accepts the unambiguous abbreviation "L" for
+    "Link" in ordinary context and for "Leap" in leap-second context.
+    Conversely, zic no longer accepts non-prefixes such as "La" as
+    abbreviations for words like "Leap".
+
+    zic no longer accepts leap second lines in ordinary input, or
+    ordinary lines in leap second input.  Formerly, zic sometimes
+    warned about this undocumented usage and handled it incorrectly.
+
+    The new macro HAVE_TZNAME governs whether the tzname external
+    variable is exported, instead of USG_COMPAT.  USG_COMPAT now
+    governs only the external variables "timezone" and "daylight".
+    This change is needed because the three variables are not in the
+    same category: although POSIX requires tzname, it specifies the
+    other two variables as optional.  Also, USG_COMPAT is now 1 or 0:
+    if not defined, the code attempts to guess it from other macros.
+
+    localtime.c and difftime.c no longer require stdio.h, and .c files
+    other than zic.c no longer require sys/wait.h.
+
+    zdump.c no longer assumes snprintf.  (Reported by Jonathan Leffler.)
+
+    Calculation of time_t extrema works around a bug in GCC 4.8.4
+    (Reported by Stan Shebs and Joseph Myers.)
+
+    zic.c no longer mistranslates formats of line numbers in non-English
+    locales.  (Problem reported by Benno Schulenberg.)
+
+    Several minor changes have been made to the code to make it a
+    bit easier to port to MS-Windows and Solaris.  (Thanks to Kees
+    Dekker for reporting the problems.)
+
+  Changes to documentation and commentary
+
+    The two new files 'theory.html' and 'calendars' contain the
+    contents of the removed file 'Theory'.  The goal is to document
+    tzdb theory more accessibly.
+
+    The zic man page now documents abbreviation rules.
+
+    tz-link.htm now covers how to apply tzdata changes to clients.
+    (Thanks to Jorge Fábregas for the AIX link.)  It also mentions MySQL.
+
+    The leap-seconds.list URL has been updated to something that is
+    more reliable for tzdb.  (Thanks to Tim Parenti and Brian Inglis.)
+
+Release 2017b - 2017-03-17 07:30:38 -0700
+
+  Briefly: Haiti has resumed DST.
+
+  Changes to past and future time stamps
+
+    Haiti resumed observance of DST in 2017.  (Thanks to Steffen Thorsen.)
+
+  Changes to past time stamps
+
+    Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
+
+    Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
+    is one byte over the POSIX limit.  (Problem reported by Derick Rethans.)
+
+  Changes to code
+
+    The reference localtime implementation now falls back on the
+    current US daylight-saving transition rules rather than the
+    1987-2006 rules.  This fallback occurs only when (1) the TZ
+    environment variable's value has a name like "AST4ADT" that asks
+    for daylight saving time but does not specify the rules, (2) there
+    is no file by that name, and (3) the TZDEFRULES file cannot be
+    loaded.  (Thanks to Tom Lane.)
+
+
+Release 2017a - 2017-02-28 00:05:36 -0800
+
+  Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
+  discontinues DST.
+
+  Changes to future time stamps
+
+    Mongolia no longer observes DST.  (Thanks to Ganbold Tsagaankhuu.)
+
+    Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
+    Its clocks diverge from America/Santiago starting 2017-05-13 at
+    23:00, hiving off a new zone America/Punta_Arenas.  Although the
+    Chilean government says this change expires in May 2019, for now
+    assume it's permanent.  (Thanks to Juan Correa and Deborah
+    Goldsmith.)  This also affects Antarctica/Palmer.
+
+  Changes to past time stamps
+
+    Fix many entries for historical time stamps for Europe/Madrid
+    before 1979, to agree with tables compiled by Pere Planesas of the
+    National Astronomical Observatory of Spain.  As a side effect,
+    this changes some time stamps for Africa/Ceuta before 1929, which
+    are probably guesswork anyway.  (Thanks to Steve Allen and
+    Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
+    correcting the 1901 transition.)
+
+    Ecuador observed DST from 1992-11-28 to 1993-02-05.
+    (Thanks to Alois Treindl.)
+
+    Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
+    (Thanks to Stepan Golosunov.)
+
+  Changes to past and future time zone abbreviations
+
+    Switch to numeric time zone abbreviations for South America, as
+    part of the ongoing project of removing invented abbreviations.
+    This avoids the need to invent an abbreviation for the new Chilean
+    new zone.  Similarly, switch from invented to numeric time zone
+    abbreviations for Afghanistan, American Samoa, the Azores,
+    Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
+    Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
+    Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
+    Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
+    the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
+    Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
+    Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
+    Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
+    Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
+    Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
+    for half-hour daylight saving time in Belize before 1944 and in
+    the Dominican Republic before 1975; and for Canary Islands before
+    1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
+    Indian Summer Time before 1942, for Indonesia before around 1964,
+    for Kenya before 1960, for Liberia before 1973, for Madeira before
+    1967, for Namibia before 1943, for the Netherlands in 1937-9, for
+    Pakistan before 1971, for Western Sahara before 1977, and for
+    Zaporozhye in 1880-1924.
+
+    For Alaska time from 1900 through 1967, instead of "CAT" use the
+    abbreviation "AST", the abbreviation commonly used at the time
+    (Atlantic Standard Time had not been standardized yet).  Use "AWT"
+    and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
+
+    Use "CST" and "CDT" instead of invented abbreviations for Macau
+    before 1999 and Taiwan before 1938, and use "JST" instead of the
+    invented abbreviation "JCST" for Japan and Korea before 1938.
+
+  Change to database entry category
+
+    Move the Pacific/Johnston link from 'australasia' to 'backward',
+    since Johnston is now uninhabited.
+
+  Changes to code
+
+    zic no longer mishandles some transitions in January 2038 when it
+    attempts to work around Qt bug 53071.  This fixes a bug affecting
+    Pacific/Tongatapu that was introduced in zic 2016e.  localtime.c
+    now contains a workaround, useful when loading a file generated by
+    a buggy zic.  (Problem and localtime.c fix reported by Bradley
+    White.)
+
+    zdump -i now outputs non-hour numeric time zone abbreviations
+    without a colon, e.g., "+0530" rather than "+05:30".  This agrees
+    with zic %z and with common practice, and simplifies auditing of
+    zdump output.
+
+    zdump is now buildable again with -DUSE_LTZ=0.
+    (Problem reported by Joseph Myers.)
+
+    zdump.c now always includes private.h, to avoid code duplication
+    with private.h.  (Problem reported by Kees Dekker.)
+
+    localtime.c no longer mishandles early or late timestamps
+    when TZ is set to a POSIX-style string that specifies DST.
+    (Problem reported by Kees Dekker.)
+
+    date and strftime now cause %z to generate "-0000" instead of
+    "+0000" when the UT offset is zero and the time zone abbreviation
+    begins with "-".
+
+  Changes to documentation and commentary
+
+    The 'Theory' file now better documents choice of historical time
+    zone abbreviations.  (Problems reported by Michael Deckers.)
+
+    tz-link.htm now covers leap smearing, which is popular in clouds.
+
+
+Release 2016j - 2016-11-22 23:17:13 -0800
+
+  Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
+
+  Changes to future time stamps
+
+    Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
+    This hives off a new zone Europe/Saratov from Europe/Volgograd.
+    (Thanks to Yuri Konotopov and Stepan Golosunov.)
+
+  Changes to past time stamps
+
+    The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
+    Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
+    1999, not fall 1994.  (Thanks to Stepan Golosunov.)
+
+  Changes to past time zone abbreviations
+
+    Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
+    summer time before 1948.  The old use of "EET" was a typo.
+
+  Changes to code
+
+    zic no longer mishandles file systems that lack hard links, fixing
+    bugs introduced in 2016g.  (Problems reported by Tom Lane.)
+    Also, when the destination already contains symbolic links, zic
+    should now work better on systems where the 'link' system call
+    does not follow symbolic links.
+
+  Changes to documentation and commentary
+
+    tz-link.htm now documents the relationship between release version
+    numbers and development-repository commit tags.  (Suggested by
+    Paul Koning.)
+
+    The 'Theory' file now documents UT.
+
+    iso3166.tab now accents "Curaçao", and commentary now mentions
+    the names "Cabo Verde" and "Czechia".  (Thanks to Jiří Boháč.)
+
+
 Release 2016i - 2016-11-01 23:19:52 -0700
 
   Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
@@ -212,7 +551,7 @@
     23 commits and some working-file changes have been made since
     release 2016g, the version number is now something like
     '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
-    Official releases uses the same version number format as before,
+    Tagged releases use the same version number format as before,
     e.g., '2016g'.  To support the more-accurate version number, its
     specification has moved from a line in the Makefile to a new
     source file 'version'.
@@ -870,9 +1209,9 @@
     been fixed.  (Thanks to Christos Zoulas for reporting most of
     these problems and for suggesting fixes.)
 
-    If USG_COMPAT is defined and the requested time stamp is standard time,
+    If USG_COMPAT is defined and the requested timestamp is standard time,
     the tz library's localtime and mktime functions now set the extern
-    variable timezone to a value appropriate for that time stamp; and
+    variable timezone to a value appropriate for that timestamp; and
     similarly for ALTZONE, daylight saving time, and the altzone variable.
     This change is a companion to the tzname change in 2014h, and is
     designed to make timezone and altzone more compatible with tzname.
@@ -879,7 +1218,7 @@
 
     The tz library's functions now set errno to EOVERFLOW if they fail
     because the result cannot be represented.  ctime and ctime_r now
-    return NULL and set errno when a time stamp is out of range, rather
+    return NULL and set errno when a timestamp is out of range, rather
     than having undefined behavior.
 
     Some bugs associated with the new 2014g functions have been fixed.
@@ -896,7 +1235,7 @@
 
 Release 2014h - 2014-09-25 18:59:03 -0700
 
-  Changes affecting past time stamps
+  Changes affecting past timestamps
 
     America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
 
@@ -904,8 +1243,8 @@
     not 1920-01-06.  The old entry was based on a misinterpretation of Shanks.
 
     Some more zones have been turned into links, when they differed
-    from existing zones only for older time stamps.  As usual,
-    these changes affect UTC offsets in pre-1970 time stamps only.
+    from existing zones only for older timestamps.  As usual,
+    these changes affect UTC offsets in pre-1970 timestamps only.
     Their old contents have been moved to the 'backzone' file.
     The affected zones are: Africa/Blantyre, Africa/Bujumbura,
     Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
@@ -917,7 +1256,7 @@
     not merely on platforms defining TM_GMTOFF.
 
     The tz library's localtime and mktime functions now set tzname to a value
-    appropriate for the requested time stamp, and zdump now uses this
+    appropriate for the requested timestamp, and zdump now uses this
     on platforms not defining TM_ZONE, fixing a 2014g regression.
     (Thanks to Tim Parenti for reporting the problem.)
 
@@ -957,13 +1296,13 @@
 
 Release 2014g - 2014-08-28 12:31:23 -0700
 
-  Changes affecting future time stamps
+  Changes affecting future timestamps
 
     Turks & Caicos is switching from US eastern time to UT -04
     year-round, modeled as a switch on 2014-11-02 at 02:00.
     [As noted in 2014j, this switch was later delayed.]
 
-  Changes affecting past time stamps
+  Changes affecting past timestamps
 
     Time in Russia or the USSR before 1926 or so has been corrected by
     a few seconds in the following zones: Asia/Irkutsk,
@@ -973,7 +1312,7 @@
     Vladimir Karpinsky.)
 
     The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
-    This affects 1911 time stamps in Africa/Bissau, Africa/Luanda,
+    This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
     Atlantic/Azores, and Atlantic/Madeira.  Also, Lisbon's pre-1912
     GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
     (Thanks to Stephen Colebourne for pointing to the decree.)
@@ -981,7 +1320,7 @@
     Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
 
     A new file 'backzone' contains data which may appeal to
-    connoisseurs of old time stamps, although it is out of scope for
+    connoisseurs of old timestamps, although it is out of scope for
     the tz database, is often poorly sourced, and contains some data
     that is known to be incorrect.  The new file is not recommended
     for ordinary use and its entries are not installed by default.
@@ -989,8 +1328,8 @@
     Isle of Man entries.)
 
     Some more zones have been turned into links, when they differed
-    from existing zones only for older time stamps.  As usual,
-    these changes affect UTC offsets in pre-1970 time stamps only.
+    from existing zones only for older timestamps.  As usual,
+    these changes affect UTC offsets in pre-1970 timestamps only.
     Their old contents have been moved to the 'backzone' file.
     The affected zones are: Africa/Bangui, Africa/Brazzaville,
     Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
@@ -1041,7 +1380,7 @@
     but does not cause other problems such as traps.
 
     If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
-    more likely to guess right for ambiguous time stamps near
+    more likely to guess right for ambiguous timestamps near
     transitions where tm_isdst does not change.
 
     If HAVE_STRFTIME_L is defined to 1, the tz library now defines
@@ -1114,7 +1453,7 @@
 
 Release 2014f - 2014-08-05 17:42:36 -0700
 
-  Changes affecting future time stamps
+  Changes affecting future timestamps
 
     Russia will subtract an hour from most of its time zones on 2014-10-26
     at 02:00 local time.  (Thanks to Alexander Krivenyshev.)
@@ -1165,13 +1504,13 @@
     These abbreviations are now used for time in Korea, Taiwan,
     and Sakhalin while controlled by Japan.
 
-  Changes affecting past time stamps
+  Changes affecting past timestamps
 
     China's five zones have been simplified to two, since the post-1970
     differences in the other three seem to have been imaginary.  The
     zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
     removed; backwards-compatibility links still work, albeit with
-    different behaviors for time stamps before May 1980.  Asia/Urumqi's
+    different behaviors for timestamps before May 1980.  Asia/Urumqi's
     1980 transition to UT +08 has been removed, so that it is now at
     +06 and not +08.  (Thanks to Luther Ma and to Alois Treindl;
     Treindl sent helpful translations of two papers by Guo Qingsheng.)
@@ -1178,7 +1517,7 @@
 
     Some zones have been turned into links, when they differed from existing
     zones only for older UTC offsets where data entries were likely invented.
-    These changes affect UTC offsets in pre-1970 time stamps only.  This is
+    These changes affect UTC offsets in pre-1970 timestamps only.  This is
     similar to the change in release 2013e, except this time for western
     Africa.  The affected zones are: Africa/Bamako, Africa/Banjul,
     Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
@@ -1323,7 +1662,7 @@
 
 Release 2014e - 2014-06-12 21:53:52 -0700
 
-  Changes affecting near-future time stamps
+  Changes affecting near-future timestamps
 
     Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
     (Thanks to Imed Chihi.)  Guess that from 2015 on Egypt will temporarily
@@ -1335,7 +1674,7 @@
     temporarily switch to standard time at 03:00 the last Saturday before
     Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
 
-  Changes affecting past time stamps
+  Changes affecting past timestamps
 
     The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
     "MSD" for Moscow's double daylight time in summer 1921.  Also, a typo
@@ -1353,7 +1692,7 @@
 
   Changes affecting code
 
-    zic no longer generates files containing time stamps before the Big Bang.
+    zic no longer generates files containing timestamps before the Big Bang.
     This works around GNOME bug 730332
     <https://bugzilla.gnome.org/show_bug.cgi?id=730332>.
     (Thanks to Leonardo Chiquitto for reporting the bug, and to
@@ -1366,7 +1705,7 @@
 
 Release 2014c - 2014-05-13 07:44:13 -0700
 
-  Changes affecting near-future time stamps
+  Changes affecting near-future timestamps
 
     Egypt observes DST starting 2014-05-15 at 24:00.
     (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
@@ -1380,7 +1719,7 @@
   Changes affecting code
 
     zic now generates transitions for minimum time values, eliminating guesswork
-    when handling low-valued time stamps.  (Thanks to Arthur David Olson.)
+    when handling low-valued timestamps.  (Thanks to Arthur David Olson.)
 
     Port to Cygwin sans glibc.  (Thanks to Arthur David Olson.)
 
@@ -1391,7 +1730,7 @@
 
 Release 2014b - 2014-03-24 21:28:50 -0700
 
-  Changes affecting near-future time stamps
+  Changes affecting near-future timestamps
 
     Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
     (Thanks to Alexander Krivenyshev.)  Move its zone.tab entry from UA to RU.
@@ -1430,12 +1769,12 @@
 
 Release 2014a - 2014-03-07 23:30:29 -0800
 
-  Changes affecting near-future time stamps
+  Changes affecting near-future timestamps
 
     Turkey begins DST on 2014-03-31, not 03-30.  (Thanks to Faruk Pasin for
     the heads-up, and to Tim Parenti for simplifying the update.)
 
-  Changes affecting past time stamps
+  Changes affecting past timestamps
 
     Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
     (Thanks to Steffen Thorsen.)
@@ -1499,13 +1838,13 @@
 
 Release 2013i - 2013-12-17 07:25:23 -0800
 
-  Changes affecting near-future time stamps:
+  Changes affecting near-future timestamps:
 
     Jordan switches back to standard time at 00:00 on December 20, 2013.
     The 2006-2011 transition schedule is planned to resume in 2014.
     (Thanks to Steffen Thorsen.)
 
-  Changes affecting past time stamps:
+  Changes affecting past timestamps:
 
     In 2004, Cuba began DST on March 28, not April 4.
     (Thanks to Steffen Thorsen.)
@@ -1529,7 +1868,7 @@
 
 Release 2013h - 2013-10-25 15:32:32 -0700
 
-  Changes affecting current and future time stamps:
+  Changes affecting current and future timestamps:
 
     Libya has switched its UT offset back to +02 without DST, instead
     of +01 with DST.  (Thanks to Even Scharning.)
@@ -1537,7 +1876,7 @@
     Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
     (Thanks to Gwillim Law.)
 
-  Changes affecting future time stamps:
+  Changes affecting future timestamps:
 
     Acre and (we guess) western Amazonas will switch from UT -04 to -05
     on 2013-11-10.  This affects America/Rio_Branco and America/Eirunepe.
@@ -1588,7 +1927,7 @@
 
 Release 2013g - 2013-09-30 21:08:26 -0700
 
-  Changes affecting current and near-future time stamps
+  Changes affecting current and near-future timestamps
 
     Morocco now observes DST from the last Sunday in March to the last
     Sunday in October, not April to September respectively.  (Thanks
@@ -1621,7 +1960,7 @@
 
 Release 2013f - 2013-09-24 23:37:36 -0700
 
-  Changes affecting near-future time stamps
+  Changes affecting near-future timestamps
 
     Tocantins will very likely not observe DST starting this spring.
     (Thanks to Steffen Thorsen.)
@@ -1668,7 +2007,7 @@
 
 Release 2013e - 2013-09-19 23:50:04 -0700
 
-  Changes affecting near-future time stamps
+  Changes affecting near-future timestamps
 
     This year Fiji will start DST on October 27, not October 20.
     (Thanks to David Wheeler for the heads-up.)  For now, guess that
@@ -1686,13 +2025,13 @@
     Use ART (UT -03, standard time), rather than WARST (also -03, but
     daylight saving time) for San Luis, Argentina since 2009.
 
-  Changes affecting Godthåb time stamps after 2037 if version mismatch
+  Changes affecting Godthåb timestamps after 2037 if version mismatch
 
     Allow POSIX-like TZ strings where the transition time's hour can
     range from -167 through 167, instead of the POSIX-required 0
     through 24.  E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
     new Fiji rules.  This is a more-compact way to represent
-    far-future time stamps for America/Godthab, America/Santiago,
+    far-future timestamps for America/Godthab, America/Santiago,
     Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
     Pacific/Easter, and Pacific/Fiji.  Other zones are unaffected by
     this change.  (Derived from a suggestion by Arthur David Olson.)
@@ -1710,12 +2049,12 @@
     embedded TZ-format string, and the tz file format version number
     has therefore been increased from 2 to 3 as a precaution.
     Version-2-based client code should continue to work as before for
-    all time stamps before 2038.  Existing version-2-based client code
+    all timestamps before 2038.  Existing version-2-based client code
     (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
-    files, and typically works in practice even for time stamps after
+    files, and typically works in practice even for timestamps after
     2037; the only known exception is America/Godthab.
 
-  Changes affecting time stamps before 1970
+  Changes affecting timestamps before 1970
 
     Pacific/Johnston is now a link to Pacific/Honolulu.  This corrects
     some errors before 1947.
@@ -1723,7 +2062,7 @@
     Some zones have been turned into links, when they differ from existing
     zones only in older data entries that were likely invented or that
     differ only in LMT or transitions from LMT.  These changes affect
-    only time stamps before 1943.  The affected zones are:
+    only timestamps before 1943.  The affected zones are:
     Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
     America/Grenada, America/Guadeloupe, America/Marigot,
     America/Montserrat, America/St_Barthelemy, America/St_Kitts,
@@ -1733,11 +2072,11 @@
     link is better for WWII-era times.)
 
     Change Kingston Mean Time from -5:07:12 to -5:07:11.  This affects
-    America/Cayman, America/Jamaica and America/Grand_Turk time stamps
+    America/Cayman, America/Jamaica and America/Grand_Turk timestamps
     from 1890 to 1912.
 
     Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
-    This affects Europe/Zurich time stamps from 1853 to 1894.  (Thanks
+    This affects Europe/Zurich timestamps from 1853 to 1894.  (Thanks
     to Alois Treindl).
 
     Change the date of the circa-1850 Zurich transition from 1849-09-12
@@ -1755,7 +2094,7 @@
     data can't be summarized using a TZ string, and uses a 402-year
     window rather than a 400-year window.  For the current data, this
     affects only the Asia/Tehran file.  It does not affect any of the
-    time stamps that this file represents, so zdump outputs the same
+    timestamps that this file represents, so zdump outputs the same
     information as before.  (Thanks to Andrew Main (Zefram).)
 
     The 'date' command has a new '-r' option, which lets you specify
@@ -1787,7 +2126,7 @@
   Changes affecting the zdump utility
 
     zdump now outputs "UT" when referring to Universal Time, not "UTC".
-    "UTC" does not make sense for time stamps that predate the introduction
+    "UTC" does not make sense for timestamps that predate the introduction
     of UTC, whereas "UT", a more-generic term, does.  (Thanks to Steve Allen
     for clarifying UT vs UTC.)
 
@@ -1798,7 +2137,7 @@
 
     Remove from zone.tab the names America/Montreal, America/Shiprock,
     and Antarctica/South_Pole, as they are equivalent to existing
-    same-country-code zones for post-1970 time stamps.  The data entries for
+    same-country-code zones for post-1970 timestamps.  The data entries for
     these names are unchanged, so the names continue to work as before.
 
   Changes affecting code internals
@@ -1816,7 +2155,7 @@
 
     The 'leapseconds' file is now generated automatically from a
     new file 'leap-seconds.list', which is a copy of
-    <ftp://time.nist.gov/pub/leap-seconds.list>.
+    <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
     A new source file 'leapseconds.awk' implements this.
     The goal is simplification of the future maintenance of 'leapseconds'.
 
@@ -1858,7 +2197,7 @@
 
       There is a new section about the accuracy of the tz database,
       describing the many ways that errors can creep in, and
-      explaining why so many of the pre-1970 time stamps are wrong or
+      explaining why so many of the pre-1970 timestamps are wrong or
       misleading (thanks to Steve Allen, Lester Caine, and Garrett
       Wollman for discussions that contributed to this).
 
@@ -1893,7 +2232,7 @@
 
 Release 2013d - 2013-07-05 07:38:01 -0700
 
-  Changes affecting future time stamps:
+  Changes affecting future timestamps:
 
     Morocco's midsummer transitions this year are July 7 and August 10,
     not July 9 and August 8.  (Thanks to Andrew Paprocki.)
@@ -1901,7 +2240,7 @@
     Israel now falls back on the last Sunday of October.
     (Thanks to Ephraim Silverberg.)
 
-  Changes affecting past time stamps:
+  Changes affecting past timestamps:
 
     Specify Jerusalem's location more precisely; this changes the pre-1880
     times by 2 s.
@@ -1939,7 +2278,7 @@
 
 Release 2013c - 2013-04-19 16:17:40 -0700
 
-  Changes affecting current and future time stamps:
+  Changes affecting current and future timestamps:
 
     Palestine observed DST starting March 29, 2013.  (Thanks to
     Steffen Thorsen.)  From 2013 on, Gaza and Hebron both observe DST,
@@ -1950,7 +2289,7 @@
     by moving the end of DST to the 4th Sunday in March every year.
     (Thanks to Carlos Raúl Perasso.)
 
-  Changes affecting past time stamps:
+  Changes affecting past timestamps:
 
     Fix some historical data for Palestine to agree with that of
     timeanddate.com, as follows:
@@ -1984,10 +2323,10 @@
 
 Release 2013b - 2013-03-10 22:33:40 -0700
 
-  Changes affecting current and future time stamps:
+  Changes affecting current and future timestamps:
 
     Haiti uses US daylight-saving rules this year, and presumably future years.
-    This changes time stamps starting today.  (Thanks to Steffen Thorsen.)
+    This changes timestamps starting today.  (Thanks to Steffen Thorsen.)
 
     Paraguay will end DST on March 24 this year.
     (Thanks to Steffen Thorsen.)  For now, assume it's just this year.
@@ -2011,7 +2350,7 @@
     The zone offset at the end of version-2-format zone files is now
     allowed to be 24:00, as per POSIX.1-2008.  (Thanks to Arthur David Olson.)
 
-  Changes affecting current and future time stamps:
+  Changes affecting current and future timestamps:
 
     Chile's 2013 rules, and we guess rules for 2014 and later, will be
     the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
@@ -2020,9 +2359,9 @@
     New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
     (Thanks to Tobias Conradi and Arthur David Olson.)
 
-  Many changes affect historical time stamps before 1940.
+  Many changes affect historical timestamps before 1940.
   These were deduced from: Milne J. Civil time. Geogr J. 1899
-  Feb;13(2):173-94 <http://www.jstor.org/stable/1774359>.
+  Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
 
   Changes affecting the code:
 
@@ -2152,7 +2491,7 @@
 
 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
 
-  Changes for Morocco's time stamps, which take effect in a couple of
+  Changes for Morocco's timestamps, which take effect in a couple of
   hours, along with infrastructure changes to accommodate how the tz
   code and data are released on IANA.
 
@@ -2296,12 +2635,12 @@
 
 Release 2011d - 2011-03-14 09:18:01 -0400
 
-  changes that impact present-day time stamps in Cuba, Samoa, and Turkey
+  changes that impact present-day timestamps in Cuba, Samoa, and Turkey
 
 
 Release 2011c - 2011-03-07 09:30:09 -0500
 
-  These do affect current time stamps in Chile and Annette Island, Canada.
+  These do affect current timestamps in Chile and Annette Island, Canada.
 
 
 Release 2011b - 2011-02-07 08:44:50 -0500
@@ -3766,7 +4105,7 @@
 numbers.  Recent releases also come in an experimental format
 consisting of a single tarball tzdb-R.tar.lz with extra data.
 
-Release time stamps are taken from the release's commit (for newer,
+Release timestamps are taken from the release's commit (for newer,
 Git-based releases), from the newest file in the tarball (for older
 releases, where this info is available) or from the email announcing
 the release (if all else fails; these are marked with a time zone of
--- contrib/tzdata/README.orig
+++ contrib/tzdata/README
@@ -10,24 +10,9 @@
 changes made by political bodies to time zone boundaries, UTC offsets,
 and daylight-saving rules.
 
-Here is a recipe for acquiring, building, installing, and testing the
-tz distribution on a GNU/Linux or similar host.
-
-To acquire the distribution, run the following shell commands:
-
-	mkdir tz
-	cd tz
-	wget --retr-symlinks 'ftp://ftp.iana.org/tz/tz*-latest.tar.gz'
-	gzip -dc tzcode-latest.tar.gz | tar -xf -
-	gzip -dc tzdata-latest.tar.gz | tar -xf -
-
-Alternatively, the following shell commands acquire the same
-distribution, with extra data useful for regression testing:
-
-	wget --retr-symlinks 'ftp://ftp.iana.org/tz/tzdb-latest.tar.lz'
-	lzip -dc tzdb-latest.tar.lz | tar -xf -
-
-Be sure to read the comments in "Makefile" and make any changes needed
+See <https://www.iana.org/time-zones/repository/tz-link.html> or the
+file tz-link.htm for how to acquire the code and data.  Once acquired,
+read the comments in the file 'Makefile' and make any changes needed
 to make things right for your system, especially if you are using some
 platform other than GNU/Linux.  Then run the following commands,
 substituting your desired installation directory for "$HOME/tzdir":
@@ -60,10 +45,6 @@
 maintainer, to whom the time zone community owes the greatest debt of all.
 None of them are responsible for remaining errors.
 
-Look in <ftp://ftp.iana.org/tz/releases/> for updated versions of these files.
-
-Please send comments or information to tz@iana.org.
-
 -----
 
 This file is in the public domain, so clarified as of 2009-05-17 by
--- contrib/tzdata/Theory.orig
+++ contrib/tzdata/Theory
@@ -1,840 +0,0 @@
-Theory and pragmatics of the tz code and data
-
-
------ Outline -----
-
-	Scope of the tz database
-	Names of time zone rules
-	Time zone abbreviations
-	Accuracy of the tz database
-	Time and date functions
-	Calendrical issues
-	Time and time zones on Mars
-
-
------ Scope of the tz database -----
-
-The tz database attempts to record the history and predicted future of
-all computer-based clocks that track civil time.  To represent this
-data, the world is partitioned into regions whose clocks all agree
-about time stamps that occur after the somewhat-arbitrary cutoff point
-of the POSIX Epoch (1970-01-01 00:00:00 UTC).  For each such region,
-the database records all known clock transitions, and labels the region
-with a notable location.  Although 1970 is a somewhat-arbitrary
-cutoff, there are significant challenges to moving the cutoff earlier
-even by a decade or two, due to the wide variety of local practices
-before computer timekeeping became prevalent.
-
-Clock transitions before 1970 are recorded for each such location,
-because most systems support time stamps before 1970 and could
-misbehave if data entries were omitted for pre-1970 transitions.
-However, the database is not designed for and does not suffice for
-applications requiring accurate handling of all past times everywhere,
-as it would take far too much effort and guesswork to record all
-details of pre-1970 civil timekeeping.
-
-As described below, reference source code for using the tz database is
-also available.  The tz code is upwards compatible with POSIX, an
-international standard for UNIX-like systems.  As of this writing, the
-current edition of POSIX is:
-
-  The Open Group Base Specifications Issue 7
-  IEEE Std 1003.1, 2013 Edition
-  <http://pubs.opengroup.org/onlinepubs/9699919799/>
-
-
-
------ Names of time zone rules -----
-
-Each of the database's time zone rules has a unique name.
-Inexperienced users are not expected to select these names unaided.
-Distributors should provide documentation and/or a simple selection
-interface that explains the names; for one example, see the 'tzselect'
-program in the tz code.  The Unicode Common Locale Data Repository
-<http://cldr.unicode.org/> contains data that may be useful for other
-selection interfaces.
-
-The time zone rule naming conventions attempt to strike a balance
-among the following goals:
-
- * Uniquely identify every region where clocks have agreed since 1970.
-   This is essential for the intended use: static clocks keeping local
-   civil time.
-
- * Indicate to experts where that region is.
-
- * Be robust in the presence of political changes.  For example, names
-   of countries are ordinarily not used, to avoid incompatibilities
-   when countries change their name (e.g. Zaire->Congo) or when
-   locations change countries (e.g. Hong Kong from UK colony to
-   China).
-
- * Be portable to a wide variety of implementations.
-
- * Use a consistent naming conventions over the entire world.
-
-Names normally have the form AREA/LOCATION, where AREA is the name
-of a continent or ocean, and LOCATION is the name of a specific
-location within that region.  North and South America share the same
-area, 'America'.  Typical names are 'Africa/Cairo', 'America/New_York',
-and 'Pacific/Honolulu'.
-
-Here are the general rules used for choosing location names,
-in decreasing order of importance:
-
-	Use only valid POSIX file name components (i.e., the parts of
-		names other than '/').  Do not use the file name
-		components '.' and '..'.  Within a file name component,
-		use only ASCII letters, '.', '-' and '_'.  Do not use
-		digits, as that might create an ambiguity with POSIX
-		TZ strings.  A file name component must not exceed 14
-		characters or start with '-'.  E.g., prefer 'Brunei'
-		to 'Bandar_Seri_Begawan'.  Exceptions: see the discussion
-		of legacy names below.
-	A name must not be empty, or contain '//', or start or end with '/'.
-	Do not use names that differ only in case.  Although the reference
-		implementation is case-sensitive, some other implementations
-		are not, and they would mishandle names differing only in case.
-	If one name A is an initial prefix of another name AB (ignoring case),
-		then B must not start with '/', as a regular file cannot have
-		the same name as a directory in POSIX.  For example,
-		'America/New_York' precludes 'America/New_York/Bronx'.
-	Uninhabited regions like the North Pole and Bouvet Island
-		do not need locations, since local time is not defined there.
-	There should typically be at least one name for each ISO 3166-1
-		officially assigned two-letter code for an inhabited country
-		or territory.
-	If all the clocks in a region have agreed since 1970,
-		don't bother to include more than one location
-		even if subregions' clocks disagreed before 1970.
-		Otherwise these tables would become annoyingly large.
-	If a name is ambiguous, use a less ambiguous alternative;
-		e.g. many cities are named San José and Georgetown, so
-		prefer 'Costa_Rica' to 'San_Jose' and 'Guyana' to 'Georgetown'.
-	Keep locations compact.  Use cities or small islands, not countries
-		or regions, so that any future time zone changes do not split
-		locations into different time zones.  E.g. prefer 'Paris'
-		to 'France', since France has had multiple time zones.
-	Use mainstream English spelling, e.g. prefer 'Rome' to 'Roma', and
-		prefer 'Athens' to the Greek 'Αθήνα' or the Romanized 'Athína'.
-		The POSIX file name restrictions encourage this rule.
-	Use the most populous among locations in a zone,
-		e.g. prefer 'Shanghai' to 'Beijing'.  Among locations with
-		similar populations, pick the best-known location,
-		e.g. prefer 'Rome' to 'Milan'.
-	Use the singular form, e.g. prefer 'Canary' to 'Canaries'.
-	Omit common suffixes like '_Islands' and '_City', unless that
-		would lead to ambiguity.  E.g. prefer 'Cayman' to
-		'Cayman_Islands' and 'Guatemala' to 'Guatemala_City',
-		but prefer 'Mexico_City' to 'Mexico' because the country
-		of Mexico has several time zones.
-	Use '_' to represent a space.
-	Omit '.' from abbreviations in names, e.g. prefer 'St_Helena'
-		to 'St._Helena'.
-	Do not change established names if they only marginally
-		violate the above rules.  For example, don't change
-		the existing name 'Rome' to 'Milan' merely because
-		Milan's population has grown to be somewhat greater
-		than Rome's.
-	If a name is changed, put its old spelling in the 'backward' file.
-		This means old spellings will continue to work.
-
-The file 'zone1970.tab' lists geographical locations used to name time
-zone rules.  It is intended to be an exhaustive list of names for
-geographic regions as described above; this is a subset of the names
-in the data.  Although a 'zone1970.tab' location's longitude
-corresponds to its LMT offset with one hour for every 15 degrees east
-longitude, this relationship is not exact.
-
-Older versions of this package used a different naming scheme,
-and these older names are still supported.
-See the file 'backward' for most of these older names
-(e.g., 'US/Eastern' instead of 'America/New_York').
-The other old-fashioned names still supported are
-'WET', 'CET', 'MET', and 'EET' (see the file 'europe').
-
-Older versions of this package defined legacy names that are
-incompatible with the first rule of location names, but which are
-still supported.  These legacy names are mostly defined in the file
-'etcetera'.  Also, the file 'backward' defines the legacy names
-'GMT0', 'GMT-0', 'GMT+0' and 'Canada/East-Saskatchewan', and the file
-'northamerica' defines the legacy names 'EST5EDT', 'CST6CDT',
-'MST7MDT', and 'PST8PDT'.
-
-Excluding 'backward' should not affect the other data.  If
-'backward' is excluded, excluding 'etcetera' should not affect the
-remaining data.
-
-
------ Time zone abbreviations -----
-
-When this package is installed, it generates time zone abbreviations
-like 'EST' to be compatible with human tradition and POSIX.
-Here are the general rules used for choosing time zone abbreviations,
-in decreasing order of importance:
-
-	Use three or more characters that are ASCII alphanumerics or '+' or '-'.
-		Previous editions of this database also used characters like
-		' ' and '?', but these characters have a special meaning to
-		the shell and cause commands like
-			set `date`
-		to have unexpected effects.
-		Previous editions of this rule required upper-case letters,
-		but the Congressman who introduced Chamorro Standard Time
-		preferred "ChST", so lower-case letters are now allowed.
-		Also, POSIX from 2001 on relaxed the rule to allow '-', '+',
-		and alphanumeric characters from the portable character set
-		in the current locale.  In practice ASCII alphanumerics and
-		'+' and '-' are safe in all locales.
-
-		In other words, in the C locale the POSIX extended regular
-		expression [-+[:alnum:]]{3,} should match the abbreviation.
-		This guarantees that all abbreviations could have been
-		specified by a POSIX TZ string.
-
-	Use abbreviations that are in common use among English-speakers,
-		e.g. 'EST' for Eastern Standard Time in North America.
-		We assume that applications translate them to other languages
-		as part of the normal localization process; for example,
-		a French application might translate 'EST' to 'HNE'.
-
-	For zones whose times are taken from a city's longitude, use the
-		traditional xMT notation, e.g. 'PMT' for Paris Mean Time.
-		The only name like this in current use is 'GMT'.
-
-	Use 'LMT' for local mean time of locations before the introduction
-		of standard time; see "Scope of the tz database".
-
-	If there is no common English abbreviation, use numeric offsets like
-		-05 and +0830 that are generated by zic's %z notation.
-
-    [The remaining guidelines predate the introduction of %z.
-    They are problematic as they mean tz data entries invent
-    notation rather than record it.  These guidelines are now
-    deprecated and the plan is to gradually move to %z for
-    inhabited locations and to "-00" for uninhabited locations.]
-
-	If there is no common English abbreviation, abbreviate the English
-		translation of the usual phrase used by native speakers.
-		If this is not available or is a phrase mentioning the country
-		(e.g. "Cape Verde Time"), then:
-
-		When a country is identified with a single or principal zone,
-			append 'T' to the country's ISO	code, e.g. 'CVT' for
-			Cape Verde Time.  For summer time append 'ST';
-			for double summer time append 'DST'; etc.
-		Otherwise, take the first three letters of an English place
-			name identifying each zone and append 'T', 'ST', etc.
-			as before; e.g. 'VLAST' for VLAdivostok Summer Time.
-
-	Use UT (with time zone abbreviation '-00') for locations while
-		uninhabited.  The leading '-' is a flag that the time
-		zone is in some sense undefined; this notation is
-		derived from Internet RFC 3339.
-
-Application writers should note that these abbreviations are ambiguous
-in practice: e.g. 'CST' has a different meaning in China than
-it does in the United States.  In new applications, it's often better
-to use numeric UT offsets like '-0600' instead of time zone
-abbreviations like 'CST'; this avoids the ambiguity.
-
-
------ Accuracy of the tz database -----
-
-The tz database is not authoritative, and it surely has errors.
-Corrections are welcome and encouraged; see the file CONTRIBUTING.
-Users requiring authoritative data should consult national standards
-bodies and the references cited in the database's comments.
-
-Errors in the tz database arise from many sources:
-
- * The tz database predicts future time stamps, and current predictions
-   will be incorrect after future governments change the rules.
-   For example, if today someone schedules a meeting for 13:00 next
-   October 1, Casablanca time, and tomorrow Morocco changes its
-   daylight saving rules, software can mess up after the rule change
-   if it blithely relies on conversions made before the change.
-
- * The pre-1970 entries in this database cover only a tiny sliver of how
-   clocks actually behaved; the vast majority of the necessary
-   information was lost or never recorded.  Thousands more zones would
-   be needed if the tz database's scope were extended to cover even
-   just the known or guessed history of standard time; for example,
-   the current single entry for France would need to split into dozens
-   of entries, perhaps hundreds.  And in most of the world even this
-   approach would be misleading due to widespread disagreement or
-   indifference about what times should be observed.  In her 2015 book
-   "The Global Transformation of Time, 1870-1950", Vanessa Ogle writes
-   "Outside of Europe and North America there was no system of time
-   zones at all, often not even a stable landscape of mean times,
-   prior to the middle decades of the twentieth century".  See:
-   Timothy Shenk, Booked: A Global History of Time. Dissent 2015-12-17
-   https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanessa-ogle
-
- * Most of the pre-1970 data entries come from unreliable sources, often
-   astrology books that lack citations and whose compilers evidently
-   invented entries when the true facts were unknown, without
-   reporting which entries were known and which were invented.
-   These books often contradict each other or give implausible entries,
-   and on the rare occasions when they are checked they are
-   typically found to be incorrect.
-
- * For the UK the tz database relies on years of first-class work done by
-   Joseph Myers and others; see <http://www.polyomino.org.uk/british-time/>.
-   Other countries are not done nearly as well.
-
- * Sometimes, different people in the same city would maintain clocks
-   that differed significantly.  Railway time was used by railroad
-   companies (which did not always agree with each other),
-   church-clock time was used for birth certificates, etc.
-   Often this was merely common practice, but sometimes it was set by law.
-   For example, from 1891 to 1911 the UT offset in France was legally
-   0:09:21 outside train stations and 0:04:21 inside.
-
- * Although a named location in the tz database stands for the
-   containing region, its pre-1970 data entries are often accurate for
-   only a small subset of that region.  For example, Europe/London
-   stands for the United Kingdom, but its pre-1847 times are valid
-   only for locations that have London's exact meridian, and its 1847
-   transition to GMT is known to be valid only for the L&NW and the
-   Caledonian railways.
-
- * The tz database does not record the earliest time for which a zone's
-   data entries are thereafter valid for every location in the region.
-   For example, Europe/London is valid for all locations in its
-   region after GMT was made the standard time, but the date of
-   standardization (1880-08-02) is not in the tz database, other than
-   in commentary.  For many zones the earliest time of validity is
-   unknown.
-
- * The tz database does not record a region's boundaries, and in many
-   cases the boundaries are not known.  For example, the zone
-   America/Kentucky/Louisville represents a region around the city of
-   Louisville, the boundaries of which are unclear.
-
- * Changes that are modeled as instantaneous transitions in the tz
-   database were often spread out over hours, days, or even decades.
-
- * Even if the time is specified by law, locations sometimes
-   deliberately flout the law.
-
- * Early timekeeping practices, even assuming perfect clocks, were
-   often not specified to the accuracy that the tz database requires.
-
- * Sometimes historical timekeeping was specified more precisely
-   than what the tz database can handle.  For example, from 1909 to
-   1937 Netherlands clocks were legally UT +00:19:32.13, but the tz
-   database cannot represent the fractional second.
-
- * Even when all the timestamp transitions recorded by the tz database
-   are correct, the tz rules that generate them may not faithfully
-   reflect the historical rules.  For example, from 1922 until World
-   War II the UK moved clocks forward the day following the third
-   Saturday in April unless that was Easter, in which case it moved
-   clocks forward the previous Sunday.  Because the tz database has no
-   way to specify Easter, these exceptional years are entered as
-   separate tz Rule lines, even though the legal rules did not change.
-
- * The tz database models pre-standard time using the proleptic Gregorian
-   calendar and local mean time (LMT), but many people used other
-   calendars and other timescales.  For example, the Roman Empire used
-   the Julian calendar, and had 12 varying-length daytime hours with a
-   non-hour-based system at night.
-
- * Early clocks were less reliable, and data entries do not represent
-   this unreliability.
-
- * As for leap seconds, civil time was not based on atomic time before
-   1972, and we don't know the history of earth's rotation accurately
-   enough to map SI seconds to historical solar time to more than
-   about one-hour accuracy.  See: Morrison LV, Stephenson FR.
-   Historical values of the Earth's clock error Delta T and the
-   calculation of eclipses. J Hist Astron. 2004;35:327-36
-   <http://adsabs.harvard.edu/full/2004JHA....35..327M>;
-   Historical values of the Earth's clock error. J Hist Astron. 2005;36:339
-   <http://adsabs.harvard.edu/full/2005JHA....36..339M>.
-
- * The relationship between POSIX time (that is, UTC but ignoring leap
-   seconds) and UTC is not agreed upon after 1972.  Although the POSIX
-   clock officially stops during an inserted leap second, at least one
-   proposed standard has it jumping back a second instead; and in
-   practice POSIX clocks more typically either progress glacially during
-   a leap second, or are slightly slowed while near a leap second.
-
- * The tz database does not represent how uncertain its information is.
-   Ideally it would contain information about when data entries are
-   incomplete or dicey.  Partial temporal knowledge is a field of
-   active research, though, and it's not clear how to apply it here.
-
-In short, many, perhaps most, of the tz database's pre-1970 and future
-time stamps are either wrong or misleading.  Any attempt to pass the
-tz database off as the definition of time should be unacceptable to
-anybody who cares about the facts.  In particular, the tz database's
-LMT offsets should not be considered meaningful, and should not prompt
-creation of zones merely because two locations differ in LMT or
-transitioned to standard time at different dates.
-
-
------ Time and date functions -----
-
-The tz code contains time and date functions that are upwards
-compatible with those of POSIX.
-
-POSIX has the following properties and limitations.
-
-*	In POSIX, time display in a process is controlled by the
-	environment variable TZ.  Unfortunately, the POSIX TZ string takes
-	a form that is hard to describe and is error-prone in practice.
-	Also, POSIX TZ strings can't deal with other (for example, Israeli)
-	daylight saving time rules, or situations where more than two
-	time zone abbreviations are used in an area.
-
-	The POSIX TZ string takes the following form:
-
-		stdoffset[dst[offset][,date[/time],date[/time]]]
-
-	where:
-
-	std and dst
-		are 3 or more characters specifying the standard
-		and daylight saving time (DST) zone names.
-		Starting with POSIX.1-2001, std and dst may also be
-		in a quoted form like "<UTC+10>"; this allows
-		"+" and "-" in the names.
-	offset
-		is of the form '[+-]hh:[mm[:ss]]' and specifies the
-		offset west of UT.  'hh' may be a single digit; 0<=hh<=24.
-		The default DST offset is one hour ahead of standard time.
-	date[/time],date[/time]
-		specifies the beginning and end of DST.  If this is absent,
-		the system supplies its own rules for DST, and these can
-		differ from year to year; typically US DST rules are used.
-	time
-		takes the form 'hh:[mm[:ss]]' and defaults to 02:00.
-		This is the same format as the offset, except that a
-		leading '+' or '-' is not allowed.
-	date
-		takes one of the following forms:
-		Jn (1<=n<=365)
-			origin-1 day number not counting February 29
-		n (0<=n<=365)
-			origin-0 day number counting February 29 if present
-		Mm.n.d (0[Sunday]<=d<=6[Saturday], 1<=n<=5, 1<=m<=12)
-			for the dth day of week n of month m of the year,
-			where week 1 is the first week in which day d appears,
-			and '5' stands for the last week in which day d appears
-			(which may be either the 4th or 5th week).
-			Typically, this is the only useful form;
-			the n and Jn forms are rarely used.
-
-	Here is an example POSIX TZ string, for US Pacific time using rules
-	appropriate from 1987 through 2006:
-
-		TZ='PST8PDT,M4.1.0/02:00,M10.5.0/02:00'
-
-	This POSIX TZ string is hard to remember, and mishandles time stamps
-	before 1987 and after 2006.  With this package you can use this
-	instead:
-
-		TZ='America/Los_Angeles'
-
-*	POSIX does not define the exact meaning of TZ values like "EST5EDT".
-	Typically the current US DST rules are used to interpret such values,
-	but this means that the US DST rules are compiled into each program
-	that does time conversion.  This means that when US time conversion
-	rules change (as in the United States in 1987), all programs that
-	do time conversion must be recompiled to ensure proper results.
-
-*	The TZ environment variable is process-global, which makes it hard
-	to write efficient, thread-safe applications that need access
-	to multiple time zones.
-
-*	In POSIX, there's no tamper-proof way for a process to learn the
-	system's best idea of local wall clock.  (This is important for
-	applications that an administrator wants used only at certain times -
-	without regard to whether the user has fiddled the "TZ" environment
-	variable.  While an administrator can "do everything in UTC" to get
-	around the problem, doing so is inconvenient and precludes handling
-	daylight saving time shifts - as might be required to limit phone
-	calls to off-peak hours.)
-
-*	POSIX provides no convenient and efficient way to determine the UT
-	offset and time zone abbreviation of arbitrary time stamps,
-	particularly for time zone settings that do not fit into the
-	POSIX model.
-
-*	POSIX requires that systems ignore leap seconds.
-
-*	The tz code attempts to support all the time_t implementations
-	allowed by POSIX.  The time_t type represents a nonnegative count of
-	seconds since 1970-01-01 00:00:00 UTC, ignoring leap seconds.
-	In practice, time_t is usually a signed 64- or 32-bit integer; 32-bit
-	signed time_t values stop working after 2038-01-19 03:14:07 UTC, so
-	new implementations these days typically use a signed 64-bit integer.
-	Unsigned 32-bit integers are used on one or two platforms,
-	and 36-bit and 40-bit integers are also used occasionally.
-	Although earlier POSIX versions allowed time_t to be a
-	floating-point type, this was not supported by any practical
-	systems, and POSIX.1-2013 and the tz code both require time_t
-	to be an integer type.
-
-These are the extensions that have been made to the POSIX functions:
-
-*	The "TZ" environment variable is used in generating the name of a file
-	from which time zone information is read (or is interpreted a la
-	POSIX); "TZ" is no longer constrained to be a three-letter time zone
-	name followed by a number of hours and an optional three-letter
-	daylight time zone name.  The daylight saving time rules to be used
-	for a particular time zone are encoded in the time zone file;
-	the format of the file allows U.S., Australian, and other rules to be
-	encoded, and allows for situations where more than two time zone
-	abbreviations are used.
-
-	It was recognized that allowing the "TZ" environment variable to
-	take on values such as "America/New_York" might cause "old" programs
-	(that expect "TZ" to have a certain form) to operate incorrectly;
-	consideration was given to using some other environment variable
-	(for example, "TIMEZONE") to hold the string used to generate the
-	time zone information file name.  In the end, however, it was decided
-	to continue using "TZ": it is widely used for time zone purposes;
-	separately maintaining both "TZ" and "TIMEZONE" seemed a nuisance;
-	and systems where "new" forms of "TZ" might cause problems can simply
-	use TZ values such as "EST5EDT" which can be used both by
-	"new" programs (a la POSIX) and "old" programs (as zone names and
-	offsets).
-
-*	The code supports platforms with a UT offset member in struct tm,
-	e.g., tm_gmtoff.
-
-*	The code supports platforms with a time zone abbreviation member in
-	struct tm, e.g., tm_zone.
-
-*	Since the "TZ" environment variable can now be used to control time
-	conversion, the "daylight" and "timezone" variables are no longer
-	needed.  (These variables are defined and set by "tzset"; however, their
-	values will not be used by "localtime.")
-
-*	Functions tzalloc, tzfree, localtime_rz, and mktime_z for
-	more-efficient thread-safe applications that need to use
-	multiple time zones.  The tzalloc and tzfree functions
-	allocate and free objects of type timezone_t, and localtime_rz
-	and mktime_z are like localtime_r and mktime with an extra
-	timezone_t argument.  The functions were inspired by NetBSD.
-
-*	A function "tzsetwall" has been added to arrange for the system's
-	best approximation to local wall clock time to be delivered by
-	subsequent calls to "localtime."  Source code for portable
-	applications that "must" run on local wall clock time should call
-	"tzsetwall();" if such code is moved to "old" systems that don't
-	provide tzsetwall, you won't be able to generate an executable program.
-	(These time zone functions also arrange for local wall clock time to be
-	used if tzset is called - directly or indirectly - and there's no "TZ"
-	environment variable; portable applications should not, however, rely
-	on this behavior since it's not the way SVR2 systems behave.)
-
-*	Negative time_t values are supported, on systems where time_t is signed.
-
-*	These functions can account for leap seconds, thanks to Bradley White.
-
-Points of interest to folks with other systems:
-
-*	Code compatible with this package is already part of many platforms,
-	including GNU/Linux, Android, the BSDs, Chromium OS, Cygwin, AIX, iOS,
-	BlackBery 10, macOS, Microsoft Windows, OpenVMS, and Solaris.
-	On such hosts, the primary use of this package
-	is to update obsolete time zone rule tables.
-	To do this, you may need to compile the time zone compiler
-	'zic' supplied with this package instead of using the system 'zic',
-	since the format of zic's input is occasionally extended,
-	and a platform may still be shipping an older zic.
-
-*	The UNIX Version 7 "timezone" function is not present in this package;
-	it's impossible to reliably map timezone's arguments (a "minutes west
-	of GMT" value and a "daylight saving time in effect" flag) to a
-	time zone abbreviation, and we refuse to guess.
-	Programs that in the past used the timezone function may now examine
-	tzname[localtime(&clock)->tm_isdst] to learn the correct time
-	zone abbreviation to use.  Alternatively, use
-	localtime(&clock)->tm_zone if this has been enabled.
-
-*	The 4.2BSD gettimeofday function is not used in this package.
-	This formerly let users obtain the current UTC offset and DST flag,
-	but this functionality was removed in later versions of BSD.
-
-*	In SVR2, time conversion fails for near-minimum or near-maximum
-	time_t values when doing conversions for places that don't use UT.
-	This package takes care to do these conversions correctly.
-	A comment in the source code tells how to get compatibly wrong
-	results.
-
-The functions that are conditionally compiled if STD_INSPIRED is defined
-should, at this point, be looked on primarily as food for thought.  They are
-not in any sense "standard compatible" - some are not, in fact, specified in
-*any* standard.  They do, however, represent responses of various authors to
-standardization proposals.
-
-Other time conversion proposals, in particular the one developed by folks at
-Hewlett Packard, offer a wider selection of functions that provide capabilities
-beyond those provided here.  The absence of such functions from this package
-is not meant to discourage the development, standardization, or use of such
-functions.  Rather, their absence reflects the decision to make this package
-contain valid extensions to POSIX, to ensure its broad acceptability.  If
-more powerful time conversion functions can be standardized, so much the
-better.
-
-
------ Interface stability -----
-
-The tz code and data supply the following interfaces:
-
- * A set of zone names as per "Names of time zone rules" above.
-
- * Library functions described in "Time and date functions" above.
-
- * The programs tzselect, zdump, and zic, documented in their man pages.
-
- * The format of zic input files, documented in the zic man page.
-
- * The format of zic output files, documented in the tzfile man page.
-
- * The format of zone table files, documented in zone1970.tab.
-
- * The format of the country code file, documented in iso3166.tab.
-
-When these interfaces are changed, an effort is made to preserve
-backward compatibility.  For example, tz data files typically do not
-rely on recently-added zic features, so that users can run older zic
-versions to process newer data files.
-
-Interfaces not listed above are less stable.  For example, users
-should not rely on particular UT offsets or abbreviations for time
-stamps, as data entries are often based on guesswork and these guesses
-may be corrected or improved.
-
-
------ Calendrical issues -----
-
-Calendrical issues are a bit out of scope for a time zone database,
-but they indicate the sort of problems that we would run into if we
-extended the time zone database further into the past.  An excellent
-resource in this area is Nachum Dershowitz and Edward M. Reingold,
-Calendrical Calculations: Third Edition, Cambridge University Press (2008)
-<http://emr.cs.iit.edu/home/reingold/calendar-book/third-edition/>.
-Other information and sources are given below.  They sometimes disagree.
-
-
-France
-
-Gregorian calendar adopted 1582-12-20.
-French Revolutionary calendar used 1793-11-24 through 1805-12-31,
-and (in Paris only) 1871-05-06 through 1871-05-23.
-
-
-Russia
-
-From Chris Carrier (1996-12-02):
-On 1929-10-01 the Soviet Union instituted an "Eternal Calendar"
-with 30-day months plus 5 holidays, with a 5-day week.
-On 1931-12-01 it changed to a 6-day week; in 1934 it reverted to the
-Gregorian calendar while retaining the 6-day week; on 1940-06-27 it
-reverted to the 7-day week.  With the 6-day week the usual days
-off were the 6th, 12th, 18th, 24th and 30th of the month.
-(Source: Evitiar Zerubavel, _The Seven Day Circle_)
-
-
-Mark Brader reported a similar story in "The Book of Calendars", edited
-by Frank Parise (1982, Facts on File, ISBN 0-8719-6467-8), page 377.  But:
-
-From: Petteri Sulonen (via Usenet)
-Date: 14 Jan 1999 00:00:00 GMT
-...
-
-If your source is correct, how come documents between 1929 and 1940 were
-still dated using the conventional, Gregorian calendar?
-
-I can post a scan of a document dated December 1, 1934, signed by
-Yenukidze, the secretary, on behalf of Kalinin, the President of the
-Executive Committee of the Supreme Soviet, if you like.
-
-
-
-Sweden (and Finland)
-
-From: Mark Brader
-Subject: Re: Gregorian reform - a part of locale?
-<news:1996Jul6.012937.29190@sq.com>
-Date: 1996-07-06
-
-In 1700, Denmark made the transition from Julian to Gregorian.  Sweden
-decided to *start* a transition in 1700 as well, but rather than have one of
-those unsightly calendar gaps :-), they simply decreed that the next leap
-year after 1696 would be in 1744 - putting the whole country on a calendar
-different from both Julian and Gregorian for a period of 40 years.
-
-However, in 1704 something went wrong and the plan was not carried through;
-they did, after all, have a leap year that year.  And one in 1708.  In 1712
-they gave it up and went back to Julian, putting 30 days in February that
-year!...
-
-Then in 1753, Sweden made the transition to Gregorian in the usual manner,
-getting there only 13 years behind the original schedule.
-
-(A previous posting of this story was challenged, and Swedish readers
-produced the following references to support it: "Tideräkning och historia"
-by Natanael Beckman (1924) and "Tid, en bok om tideräkning och
-kalenderväsen" by Lars-Olof Lodén (1968).
-
-
-Grotefend's data
-
-From: "Michael Palmer" [with one obvious typo fixed]
-Subject: Re: Gregorian Calendar (was Re: Another FHC related question
-Newsgroups: soc.genealogy.german
-Date: Tue, 9 Feb 1999 02:32:48 -800
-...
-
-The following is a(n incomplete) listing, arranged chronologically, of
-European states, with the date they converted from the Julian to the
-Gregorian calendar:
-
-04/15 Oct 1582 - Italy (with exceptions), Spain, Portugal, Poland (Roman
-                 Catholics and Danzig only)
-09/20 Dec 1582 - France, Lorraine
-
-21 Dec 1582/
-   01 Jan 1583 - Holland, Brabant, Flanders, Hennegau
-10/21 Feb 1583 - bishopric of Liege (Lüttich)
-13/24 Feb 1583 - bishopric of Augsburg
-04/15 Oct 1583 - electorate of Trier
-05/16 Oct 1583 - Bavaria, bishoprics of Freising, Eichstedt, Regensburg,
-                 Salzburg, Brixen
-13/24 Oct 1583 - Austrian Oberelsaß and Breisgau
-20/31 Oct 1583 - bishopric of Basel
-02/13 Nov 1583 - duchy of Jülich-Berg
-02/13 Nov 1583 - electorate and city of Köln
-04/15 Nov 1583 - bishopric of Würzburg
-11/22 Nov 1583 - electorate of Mainz
-16/27 Nov 1583 - bishopric of Strassburg and the margraviate of Baden
-17/28 Nov 1583 - bishopric of Münster and duchy of Cleve
-14/25 Dec 1583 - Steiermark
-
-06/17 Jan 1584 - Austria and Bohemia
-11/22 Jan 1584 - Lucerne, Uri, Schwyz, Zug, Freiburg, Solothurn
-12/23 Jan 1584 - Silesia and the Lausitz
-22 Jan/
-   02 Feb 1584 - Hungary (legally on 21 Oct 1587)
-      Jun 1584 - Unterwalden
-01/12 Jul 1584 - duchy of Westfalen
-
-16/27 Jun 1585 - bishopric of Paderborn
-
-14/25 Dec 1590 - Transylvania
-
-22 Aug/
-   02 Sep 1612 - duchy of Prussia
-
-13/24 Dec 1614 - Pfalz-Neuburg
-
-          1617 - duchy of Kurland (reverted to the Julian calendar in
-                 1796)
-
-          1624 - bishopric of Osnabrück
-
-          1630 - bishopric of Minden
-
-15/26 Mar 1631 - bishopric of Hildesheim
-
-          1655 - Kanton Wallis
-
-05/16 Feb 1682 - city of Strassburg
-
-18 Feb/
-   01 Mar 1700 - Protestant Germany (including Swedish possessions in
-                 Germany), Denmark, Norway
-30 Jun/
-   12 Jul 1700 - Gelderland, Zutphen
-10 Nov/
-   12 Dec 1700 - Utrecht, Overijssel
-
-31 Dec 1700/
-   12 Jan 1701 - Friesland, Groningen, Zürich, Bern, Basel, Geneva,
-                 Turgau, and Schaffhausen
-
-          1724 - Glarus, Appenzell, and the city of St. Gallen
-
-01 Jan 1750    - Pisa and Florence
-
-02/14 Sep 1752 - Great Britain
-
-17 Feb/
-   01 Mar 1753 - Sweden
-
-1760-1812      - Graubünden
-
-The Russian empire (including Finland and the Baltic states) did not
-convert to the Gregorian calendar until the Soviet revolution of 1917.
-
-Source: H. Grotefend, _Taschenbuch der Zeitrechnung des deutschen
-Mittelalters und der Neuzeit_, herausgegeben von Dr. O. Grotefend
-(Hannover: Hahnsche Buchhandlung, 1941), pp. 26-28.
-
-
------ Time and time zones on Mars -----
-
-Some people's work schedules use Mars time.  Jet Propulsion Laboratory
-(JPL) coordinators have kept Mars time on and off at least since 1997
-for the Mars Pathfinder mission.  Some of their family members have
-also adapted to Mars time.  Dozens of special Mars watches were built
-for JPL workers who kept Mars time during the Mars Exploration
-Rovers mission (2004).  These timepieces look like normal Seikos and
-Citizens but use Mars seconds rather than terrestrial seconds.
-
-A Mars solar day is called a "sol" and has a mean period equal to
-about 24 hours 39 minutes 35.244 seconds in terrestrial time.  It is
-divided into a conventional 24-hour clock, so each Mars second equals
-about 1.02749125 terrestrial seconds.
-
-The prime meridian of Mars goes through the center of the crater
-Airy-0, named in honor of the British astronomer who built the
-Greenwich telescope that defines Earth's prime meridian.  Mean solar
-time on the Mars prime meridian is called Mars Coordinated Time (MTC).
-
-Each landed mission on Mars has adopted a different reference for
-solar time keeping, so there is no real standard for Mars time zones.
-For example, the Mars Exploration Rover project (2004) defined two
-time zones "Local Solar Time A" and "Local Solar Time B" for its two
-missions, each zone designed so that its time equals local true solar
-time at approximately the middle of the nominal mission.  Such a "time
-zone" is not particularly suited for any application other than the
-mission itself.
-
-Many calendars have been proposed for Mars, but none have achieved
-wide acceptance.  Astronomers often use Mars Sol Date (MSD) which is a
-sequential count of Mars solar days elapsed since about 1873-12-29
-12:00 GMT.
-
-The tz database does not currently support Mars time, but it is
-documented here in the hopes that support will be added eventually.
-
-Sources:
-
-Michael Allison and Robert Schmunk,
-"Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock"
-<http://www.giss.nasa.gov/tools/mars24/help/notes.html> (2012-08-08).
-
-Jia-Rui Chong, "Workdays Fit for a Martian", Los Angeles Times
-<http://articles.latimes.com/2004/jan/14/science/sci-marstime14>
-(2004-01-14), pp A1, A20-A21.
-
-Tom Chmielewski, "Jet Lag Is Worse on Mars", The Atlantic (2015-02-26)
-<http://www.theatlantic.com/technology/archive/2015/02/jet-lag-is-worse-on-mars/386033/>
-
------
-
-This file is in the public domain, so clarified as of 2009-05-17 by
-Arthur David Olson.
-
------
-Local Variables:
-coding: utf-8
-End:
--- contrib/tzdata/africa.orig
+++ contrib/tzdata/africa
@@ -6,7 +6,7 @@
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
-# From Paul Eggert (2014-10-31):
+# From Paul Eggert (2017-02-20):
 #
 # Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
@@ -13,8 +13,8 @@
 # San Diego: ACS Publications, Inc. (2003).
 # Unfortunately this book contains many errors and cites no sources.
 #
-# Gwillim Law writes that a good source
-# for recent time zone data is the International Air Transport
+# Many years ago Gwillim Law wrote that a good source
+# for time zone data was the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
 # of the IATA's data after 1990.  Except where otherwise noted,
@@ -26,44 +26,38 @@
 #
 # For data circa 1899, a common source is:
 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
-# http://www.jstor.org/stable/1774359
+# https://www.jstor.org/stable/1774359
 #
 # A reliable and entertaining source about time zones is
 # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
 #
+# European-style abbreviations are commonly used along the Mediterranean.
+# For sub-Saharan Africa abbreviations were less standardized.
 # Previous editions of this database used WAT, CAT, SAT, and EAT
-# for +0:00 through +3:00, respectively,
-# but Mark R V Murray reports that
-# 'SAST' is the official abbreviation for +2:00 in the country of South Africa,
-# 'CAT' is commonly used for +2:00 in countries north of South Africa, and
-# 'WAT' is probably the best name for +1:00, as the common phrase for
+# for UT +00 through +03, respectively,
+# but in 1997 Mark R V Murray reported that
+# 'SAST' is the official abbreviation for +02 in the country of South Africa,
+# 'CAT' is commonly used for +02 in countries north of South Africa, and
+# 'WAT' is probably the best name for +01, as the common phrase for
 # the area that includes Nigeria is "West Africa".
-# He has heard of "Western Sahara Time" for +0:00 but can find no reference.
 #
-# To make things confusing, 'WAT' seems to have been used for -1:00 long ago;
-# I'd guess that this was because people needed _some_ name for -1:00,
-# and at the time, far west Africa was the only major land area in -1:00.
-# This usage is now obsolete, as the last use of -1:00 on the African
-# mainland seems to have been 1976 in Western Sahara.
+# To summarize, the following abbreviations seemed to have some currency:
+#	 +00	GMT	Greenwich Mean Time
+#	 +02	CAT	Central Africa Time
+#	 +02	SAST	South Africa Standard Time
+# and Murray suggested the following abbreviation:
+#	 +01	WAT	West Africa Time
+# Murray's suggestion seems to have caught on in news reports and the like.
+# I vaguely recall 'WAT' also being used for -01 in the past but
+# cannot now come up with solid citations.
 #
-# To summarize, the following abbreviations seem to have some currency:
-#	-1:00	WAT	West Africa Time (no longer used)
-#	 0:00	GMT	Greenwich Mean Time
-#	 2:00	CAT	Central Africa Time
-#	 2:00	SAST	South Africa Standard Time
-# and Murray suggests the following abbreviation:
-#	 1:00	WAT	West Africa Time
-# I realize that this leads to 'WAT' being used for both -1:00 and 1:00
-# for times before 1976, but this is the best I can think of
-# until we get more information.
-#
 # I invented the following abbreviations; corrections are welcome!
-#	 2:00	WAST	West Africa Summer Time
-#	 2:30	BEAT	British East Africa Time (no longer used)
-#	 2:45	BEAUT	British East Africa Unified Time (no longer used)
-#	 3:00	CAST	Central Africa Summer Time (no longer used)
-#	 3:00	SAST	South Africa Summer Time (no longer used)
-#	 3:00	EAT	East Africa Time
+#	 +02	WAST	West Africa Summer Time
+#	 +03	CAST	Central Africa Summer Time (no longer used)
+#	 +03	SAST	South Africa Summer Time (no longer used)
+#	 +03	EAT	East Africa Time
+# 'EAT' also seems to have caught on; the others are rare but are paired
+# with better-attested non-DST abbreviations.
 
 # Algeria
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
@@ -119,19 +113,19 @@
 # Cameroon
 # See Africa/Lagos.
 
-# Cape Verde
+# Cape Verde / Cabo Verde
 #
-# Shanks gives 1907 for the transition to CVT.
+# Shanks gives 1907 for the transition to +02.
 # Perhaps the 1911-05-26 Portuguese decree
-# http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
+# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
 # merely made it official?
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Atlantic/Cape_Verde -1:34:04 -	LMT	1907        # Praia
-			-2:00	-	CVT	1942 Sep
-			-2:00	1:00	CVST	1945 Oct 15
-			-2:00	-	CVT	1975 Nov 25  2:00
-			-1:00	-	CVT
+			-2:00	-	-02	1942 Sep
+			-2:00	1:00	-01	1945 Oct 15
+			-2:00	-	-02	1975 Nov 25  2:00
+			-1:00	-	-01
 
 # Central African Republic
 # See Africa/Lagos.
@@ -224,7 +218,7 @@
 # saving time in Egypt will end in the night of 2007-09-06 to 2007-09-07.
 # From Jesper Nørgaard Welen (2007-08-15): [The following agree:]
 # http://www.nentjes.info/Bill/bill5.htm
-# http://www.timeanddate.com/worldclock/city.html?n=53
+# https://www.timeanddate.com/worldclock/city.html?n=53
 # From Steffen Thorsen (2007-09-04): The official information...:
 # http://www.sis.gov.eg/En/EgyptOnline/Miscellaneous/000002/0207000000000000001580.htm
 Rule	Egypt	2007	only	-	Sep	Thu>=1	24:00	0	-
@@ -262,8 +256,8 @@
 # timeanddate[2] and another site I've found[3] also support that.
 #
 # [1] https://bugzilla.redhat.com/show_bug.cgi?id=492263
-# [2] http://www.timeanddate.com/worldclock/clockchange.html?n=53
-# [3] http://wwp.greenwichmeantime.com/time-zone/africa/egypt/
+# [2] https://www.timeanddate.com/worldclock/clockchange.html?n=53
+# [3] https://wwp.greenwichmeantime.com/time-zone/africa/egypt/
 
 # From Arthur David Olson (2009-04-20):
 # In 2009 (and for the next several years), Ramadan ends before the fourth
@@ -273,10 +267,10 @@
 # From Steffen Thorsen (2009-08-11):
 # We have been able to confirm the August change with the Egyptian Cabinet
 # Information and Decision Support Center:
-# http://www.timeanddate.com/news/time/egypt-dst-ends-2009.html
+# https://www.timeanddate.com/news/time/egypt-dst-ends-2009.html
 #
 # The Middle East News Agency
-# http://www.mena.org.eg/index.aspx
+# https://www.mena.org.eg/index.aspx
 # also reports "Egypt starts winter time on August 21"
 # today in article numbered "71, 11/08/2009 12:25 GMT."
 # Only the title above is available without a subscription to their service,
@@ -326,7 +320,7 @@
 # Thursday of April....  Clocks will still be turned back for Ramadan, but
 # dates not yet announced....
 # http://almogaz.com/news/weird-news/2015/04/05/1947105 ...
-# http://www.timeanddate.com/news/time/egypt-starts-dst-2015.html
+# https://www.timeanddate.com/news/time/egypt-starts-dst-2015.html
 
 # From Ahmed Nazmy (2015-04-20):
 # Egypt's ministers cabinet just announced ... that it will cancel DST at
@@ -388,7 +382,7 @@
 Rule	Ghana	1920	1942	-	Dec	31	0:00	0	GMT
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Accra	-0:00:52 -	LMT	1918
-			 0:00	Ghana	%s
+			 0:00	Ghana	GMT/+0020
 
 # Guinea
 # See Africa/Abidjan.
@@ -397,12 +391,12 @@
 #
 # Shanks gives 1911-05-26 for the transition to WAT,
 # evidently confusing the date of the Portuguese decree
-# http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
+# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
 # with the date that it took effect, namely 1912-01-01.
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Bissau	-1:02:20 -	LMT	1912 Jan  1
-			-1:00	-	WAT	1975
+			-1:00	-	-01	1975
 			 0:00	-	GMT
 
 # Kenya
@@ -409,8 +403,8 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Nairobi	2:27:16	-	LMT	1928 Jul
 			3:00	-	EAT	1930
-			2:30	-	BEAT	1940
-			2:45	-	BEAUT	1960
+			2:30	-	+0230	1940
+			2:45	-	+0245	1960
 			3:00	-	EAT
 Link Africa/Nairobi Africa/Addis_Ababa	 # Ethiopia
 Link Africa/Nairobi Africa/Asmara	 # Eritrea
@@ -426,18 +420,25 @@
 # See Africa/Johannesburg.
 
 # Liberia
-# From Paul Eggert (2006-03-22):
-# In 1972 Liberia was the last country to switch
-# from a UTC offset that was not a multiple of 15 or 20 minutes.
-# Howse reports that it was in honor of their president's birthday.
-# Shank & Pottenger report the date as May 1, whereas Howse reports Jan;
-# go with Shanks & Pottenger.
-# For Liberia before 1972, Shanks & Pottenger report -0:44, whereas Howse and
-# Whitman each report -0:44:30; go with the more precise figure.
+#
+# From Paul Eggert (2017-03-02):
+#
+# The Nautical Almanac for the Year 1970, p 264, is the source for -0:44:30.
+#
+# In 1972 Liberia was the last country to switch from a UTC offset
+# that was not a multiple of 15 or 20 minutes.  The 1972 change was on
+# 1972-01-07, according to an entry dated 1972-01-04 on p 330 of:
+# Presidential Papers: First year of the administration of
+# President William R. Tolbert, Jr., July 23, 1971-July 31, 1972.
+# Monrovia: Executive Mansion.
+#
+# Use the abbreviation "MMT" before 1972, as the more-accurate numeric
+# abbreviation "-004430" would be one byte over the POSIX limit.
+#
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Monrovia	-0:43:08 -	LMT	1882
 			-0:43:08 -	MMT	1919 Mar # Monrovia Mean Time
-			-0:44:30 -	LRT	1972 May # Liberia Time
+			-0:44:30 -	MMT	1972 Jan 7 # approximately MMT
 			 0:00	-	GMT
 
 ###############################################################################
@@ -446,11 +447,11 @@
 
 # From Even Scharning (2012-11-10):
 # Libya set their time one hour back at 02:00 on Saturday November 10.
-# http://www.libyaherald.com/2012/11/04/clocks-to-go-back-an-hour-on-saturday/
+# https://www.libyaherald.com/2012/11/04/clocks-to-go-back-an-hour-on-saturday/
 # Here is an official source [in Arabic]: http://ls.ly/fb6Yc
 #
 # Steffen Thorsen forwarded a translation (2012-11-10) in
-# http://mm.icann.org/pipermail/tz/2012-November/018451.html
+# https://mm.icann.org/pipermail/tz/2012-November/018451.html
 #
 # From Tim Parenti (2012-11-11):
 # Treat the 2012-11-10 change as a zone change from UTC+2 to UTC+1.
@@ -461,7 +462,7 @@
 # From Even Scharning (2013-10-25):
 # The scheduled end of DST in Libya on Friday, October 25, 2013 was
 # cancelled yesterday....
-# http://www.libyaherald.com/2013/10/24/correction-no-time-change-tomorrow/
+# https://www.libyaherald.com/2013/10/24/correction-no-time-change-tomorrow/
 #
 # From Paul Eggert (2013-10-25):
 # For now, assume they're reverting to the pre-2012 rules of permanent UT +02.
@@ -514,7 +515,7 @@
 # basis....
 # It seems that Mauritius observed daylight saving time from 1982-10-10 to
 # 1983-03-20 as well, but that was not successful....
-# http://www.timeanddate.com/news/time/mauritius-daylight-saving-time.html
+# https://www.timeanddate.com/news/time/mauritius-daylight-saving-time.html
 
 # From Alex Krivenyshev (2008-06-25):
 # http://economicdevelopment.gov.mu/portal/site/Mainhomepage/menuitem.a42b24128104d9845dabddd154508a0c/?content_id=0a7cee8b5d69a110VgnVCM1000000a04a8c0RCRD
@@ -582,7 +583,7 @@
 # http://lexpress.mu/Story/3398~Beebeejaun---Les-objectifs-d-%C3%A9conomie-d-%C3%A9nergie-de-l-heure-d-%C3%A9t%C3%A9-ont-%C3%A9t%C3%A9-atteints-
 #
 # Our wrap-up:
-# http://www.timeanddate.com/news/time/mauritius-dst-will-not-repeat.html
+# https://www.timeanddate.com/news/time/mauritius-dst-will-not-repeat.html
 
 # From Arthur David Olson (2009-07-11):
 # The "mauritius-dst-will-not-repeat" wrapup includes this:
@@ -596,7 +597,7 @@
 Rule Mauritius	2009	only	-	Mar	lastSun	2:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
-			4:00 Mauritius	MU%sT	# Mauritius Time
+			4:00 Mauritius	+04/+05
 # Agalega Is, Rodriguez
 # no information; probably like Indian/Mauritius
 
@@ -614,7 +615,7 @@
 # be one hour ahead of GMT between 1 June and 27 September, according to
 # Communication Minister and Government Spokesman, Khalid Naciri...."
 #
-# http://www.worldtimezone.net/dst_news/dst_news_morocco01.html
+# http://www.worldtimezone.com/dst_news/dst_news_morocco01.html
 # http://en.afrik.com/news11892.html
 
 # From Alex Krivenyshev (2008-05-09):
@@ -627,7 +628,7 @@
 
 # From Patrice Scattolin (2008-05-09):
 # According to this article:
-# http://www.avmaroc.com/actualite/heure-dete-comment-a127896.html
+# https://www.avmaroc.com/actualite/heure-dete-comment-a127896.html
 # (and republished here: <http://www.actu.ma/heure-dete-comment_i127896_0.html>)
 # the changes occur at midnight:
 #
@@ -649,7 +650,7 @@
 # posted in English).
 #
 # The following Google query will generate many relevant hits:
-# http://www.google.com/search?hl=en&q=Conseil+de+gouvernement+maroc+heure+avance&btnG=Search
+# https://www.google.com/search?hl=en&q=Conseil+de+gouvernement+maroc+heure+avance&btnG=Search
 
 # From Steffen Thorsen (2008-08-27):
 # Morocco will change the clocks back on the midnight between August 31
@@ -660,7 +661,7 @@
 # http://www.menara.ma/fr/Actualites/Maroc/Societe/ci.retour_a_l_heure_gmt_a_partir_du_dimanche_31_aout_a_minuit_officiel_.default
 #
 # We have some further details posted here:
-# http://www.timeanddate.com/news/time/morocco-ends-dst-early-2008.html
+# https://www.timeanddate.com/news/time/morocco-ends-dst-early-2008.html
 
 # From Steffen Thorsen (2009-03-17):
 # Morocco will observe DST from 2009-06-01 00:00 to 2009-08-21 00:00 according
@@ -670,7 +671,7 @@
 # (French)
 #
 # Our summary:
-# http://www.timeanddate.com/news/time/morocco-starts-dst-2009.html
+# https://www.timeanddate.com/news/time/morocco-starts-dst-2009.html
 
 # From Alexander Krivenyshev (2009-03-17):
 # Here is a link to official document from Royaume du Maroc Premier Ministre,
@@ -693,7 +694,7 @@
 # http://www.lavieeco.com/actualites/4099-le-maroc-passera-a-l-heure-d-ete-gmt1-le-2-mai.html
 # (French)
 # Our page:
-# http://www.timeanddate.com/news/time/morocco-starts-dst-2010.html
+# https://www.timeanddate.com/news/time/morocco-starts-dst-2010.html
 
 # From Dan Abitol (2011-03-30):
 # ...Rules for Africa/Casablanca are the following (24h format)
@@ -710,7 +711,7 @@
 # They said that the decision was already taken.
 #
 # More articles in the press
-# http://www.yabiladi.com/articles/details/5058/secret-l-heure-d-ete-maroc-leve.html
+# https://www.yabiladi.com/articles/details/5058/secret-l-heure-d-ete-maroc-leve.html
 # http://www.lematin.ma/Actualite/Express/Article.asp?id=148923
 # http://www.lavieeco.com/actualite/Le-Maroc-passe-sur-GMT%2B1-a-partir-de-dim
 
@@ -802,7 +803,7 @@
 # 1433 (18 April 2012) and the decision of the Head of Government of
 # 16 N. 3-29-15 Chaaban 1435 (4 June 2015).
 # Source (french):
-# http://lnt.ma/le-maroc-reculera-dune-heure-le-dimanche-14-juin/
+# https://lnt.ma/le-maroc-reculera-dune-heure-le-dimanche-14-juin/
 #
 # From Milamber (2015-06-09):
 # http://www.mmsp.gov.ma/fr/actualites.aspx?id=863
@@ -811,7 +812,7 @@
 # [The gov.ma announcement] would (probably) make the switch on 2015-07-19 go
 # from 03:00 to 04:00 rather than from 02:00 to 03:00, as in the patch....
 # I think the patch is correct and the quoted text is wrong; the text in
-# <http://lnt.ma/le-maroc-reculera-dune-heure-le-dimanche-14-juin/> agrees
+# <https://lnt.ma/le-maroc-reculera-dune-heure-le-dimanche-14-juin/> agrees
 # with the patch.
 
 # From Paul Eggert (2015-06-08):
@@ -915,7 +916,7 @@
 # since most of it was then controlled by Morocco.
 
 Zone Africa/El_Aaiun	-0:52:48 -	LMT	1934 Jan # El Aaiún
-			-1:00	-	WAT	1976 Apr 14
+			-1:00	-	-01	1976 Apr 14
 			 0:00	Morocco	WE%sT
 
 # Mozambique
@@ -922,7 +923,7 @@
 #
 # Shanks gives 1903-03-01 for the transition to CAT.
 # Perhaps the 1911-05-26 Portuguese decree
-# http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
+# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
 # merely made it official?
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
@@ -936,10 +937,18 @@
 Link Africa/Maputo Africa/Lubumbashi	# E Dem. Rep. of Congo
 Link Africa/Maputo Africa/Lusaka	# Zambia
 
+
 # Namibia
-# The 1994-04-03 transition is from Shanks & Pottenger.
-# Shanks & Pottenger report no DST after 1998-04; go with IATA.
 
+# From Arthur David Olson (2017-08-09):
+# The text of the "Namibia Time Act, 1994" is available online at
+# www.lac.org.na/laws/1994/811.pdf
+# and includes this nugget:
+# Notwithstanding the provisions of subsection (2) of section 1, the
+# first winter period after the commencement of this Act shall
+# commence at OOhOO on Monday 21 March 1994 and shall end at 02h00 on
+# Sunday 4 September 1994.
+
 # From Petronella Sibeene (2007-03-30):
 # http://allafrica.com/stories/200703300178.html
 # While the entire country changes its time, Katima Mulilo and other
@@ -949,21 +958,35 @@
 # the country are close to 40 minutes earlier in sunrise than the rest
 # of the country.
 #
-# From Paul Eggert (2007-03-31):
-# Apparently the Caprivi Strip informally observes Botswana time, but
-# we have no details.  In the meantime people there can use Africa/Gaborone.
+# From Paul Eggert (2017-02-22):
+# Although the Zambezi Region (formerly known as Caprivi) informally
+# observes Botswana time, we have no details about historical practice.
+# In the meantime people there can use Africa/Gaborone.
+# See: Immanuel S. The Namibian. 2017-02-23.
+# https://www.namibian.com.na/51480/read/Time-change-divides-lawmakers
 
+# From Steffen Thorsen (2017-08-09):
+# Namibia is going to change their time zone to what is now their DST:
+# https://www.newera.com.na/2017/02/23/namibias-winter-time-might-be-repealed/
+# This video is from the government decision:
+# https://www.nbc.na/news/na-passes-namibia-time-bill-repealing-1994-namibia-time-act.8665
+# We have made the assumption so far that they will change their time zone at
+# the same time they would normally start DST, the first Sunday in September:
+# https://www.timeanddate.com/news/time/namibia-new-time-zone.html
+
 # RULE	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Namibia	1994	max	-	Sep	Sun>=1	2:00	1:00	S
-Rule	Namibia	1995	max	-	Apr	Sun>=1	2:00	0	-
+Rule	Namibia	1994	only	-	Mar	21	0:00	0	-
+Rule	Namibia	1994	2016	-	Sep	Sun>=1	2:00	1:00	S
+Rule	Namibia	1995	2017	-	Apr	Sun>=1	2:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
-			1:30	-	SWAT	1903 Mar    # SW Africa Time
+			1:30	-	+0130	1903 Mar
 			2:00	-	SAST	1942 Sep 20  2:00
 			2:00	1:00	SAST	1943 Mar 21  2:00
 			2:00	-	SAST	1990 Mar 21 # independence
-			2:00	-	CAT	1994 Apr  3
-			1:00	Namibia	WA%sT
+			2:00	-	CAT	1994 Mar 21  0:00
+			1:00	Namibia	WA%sT	2017 Sep  3  2:00
+			2:00	-	CAT
 
 # Niger
 # See Africa/Lagos.
@@ -985,7 +1008,7 @@
 # Réunion
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Indian/Reunion	3:41:52 -	LMT	1911 Jun # Saint-Denis
-			4:00	-	RET	# Réunion Time
+			4:00	-	+04
 #
 # Crozet Islands also observes Réunion time; see the 'antarctica' file.
 #
@@ -1020,7 +1043,7 @@
 # Seychelles
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Indian/Mahe	3:41:48 -	LMT	1906 Jun # Victoria
-			4:00	-	SCT	# Seychelles Time
+			4:00	-	+04
 # From Paul Eggert (2001-05-30):
 # Aldabra, Farquhar, and Desroches, originally dependencies of the
 # Seychelles, were transferred to the British Indian Ocean Territory
@@ -1050,7 +1073,7 @@
 # no information
 
 # Sudan
-#
+
 # From <http://www.sunanews.net/sn13jane.html>
 # Sudan News Agency (2000-01-13),
 # also reported by Michaël De Beukelaer-Dossche via Steffen Thorsen:
@@ -1057,7 +1080,17 @@
 # Clocks will be moved ahead for 60 minutes all over the Sudan as of noon
 # Saturday....  This was announced Thursday by Caretaker State Minister for
 # Manpower Abdul-Rahman Nur-Eddin.
+
+# From Ahmed Atyya, National Telecommunications Corp. (NTC), Sudan (2017-10-17):
+# ... the Republic of Sudan is going to change the time zone from (GMT+3:00)
+# to (GMT+ 2:00) starting from Wednesday 1 November 2017.
 #
+# From Paul Eggert (2017-10-18):
+# A scanned copy (in Arabic) of Cabinet Resolution No. 352 for the
+# year 2017 can be found as an attachment in email today from Yahia
+# Abdalla of NTC, archived at:
+# https://mm.icann.org/pipermail/tz/2017-October/025333.html
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Sudan	1970	only	-	May	 1	0:00	1:00	S
 Rule	Sudan	1970	1985	-	Oct	15	0:00	0	-
@@ -1066,10 +1099,14 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Khartoum	2:10:08 -	LMT	1931
 			2:00	Sudan	CA%sT	2000 Jan 15 12:00
-			3:00	-	EAT
+			3:00	-	EAT	2017 Nov  1
+			2:00	-	CAT
 
 # South Sudan
-Link Africa/Khartoum Africa/Juba
+# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
+Zone	Africa/Juba	2:06:28 -	LMT	1931
+			2:00	Sudan	CA%sT	2000 Jan 15 12:00
+			3:00	-	EAT
 
 # Swaziland
 # See Africa/Johannesburg.
@@ -1107,11 +1144,11 @@
 # According to several news sources, Tunisia will not observe DST this year.
 # (Arabic)
 # http://www.elbashayer.com/?page=viewn&nid=42546
-# http://www.babnet.net/kiwidetail-15295.asp
+# https://www.babnet.net/kiwidetail-15295.asp
 #
 # We have also confirmed this with the US embassy in Tunisia.
 # We have a wrap-up about this on the following page:
-# http://www.timeanddate.com/news/time/tunisia-cancels-dst-2009.html
+# https://www.timeanddate.com/news/time/tunisia-cancels-dst-2009.html
 
 # From Alexander Krivenyshev (2009-03-17):
 # Here is a link to Tunis Afrique Presse News Agency
--- contrib/tzdata/antarctica.orig
+++ contrib/tzdata/antarctica
@@ -26,7 +26,7 @@
 # Heard Island, McDonald Islands (uninhabited)
 #	previously sealers and scientific personnel wintered
 #	Margaret Turner reports
-#	http://web.archive.org/web/20021204222245/http://www.dstc.qut.edu.au/DST/marg/daylight.html
+#	https://web.archive.org/web/20021204222245/http://www.dstc.qut.edu.au/DST/marg/daylight.html
 #	(1999-09-30) that they're UT +05, with no DST;
 #	presumably this is when they have visitors.
 #
@@ -47,7 +47,7 @@
 # http://www.aad.gov.au/default.asp?casid=37079
 #
 # We have more background information here:
-# http://www.timeanddate.com/news/time/antarctica-new-times.html
+# https://www.timeanddate.com/news/time/antarctica-new-times.html
 
 # From Steffen Thorsen (2010-03-10):
 # We got these changes from the Australian Antarctic Division: ...
@@ -62,7 +62,7 @@
 # - Mawson station stays on UTC+5.
 #
 # Background:
-# http://www.timeanddate.com/news/time/antartica-time-changes-2010.html
+# https://www.timeanddate.com/news/time/antartica-time-changes-2010.html
 
 # From Steffen Thorsen (2016-10-28):
 # Australian Antarctica Division informed us that Casey changed time
@@ -110,7 +110,8 @@
 # O'Higgins, Antarctic Peninsula, -6319-05704, since 1948-02
 # Prat, -6230-05941
 # Villa Las Estrellas (a town), around the Frei base, since 1984-04-09
-# These locations have always used Santiago time; use TZ='America/Santiago'.
+# These locations employ Region of Magallanes time; use
+# TZ='America/Punta_Arenas'.
 
 # China - year-round bases
 # Great Wall, King George Island, -6213-05858, since 1985-02-20
@@ -144,7 +145,7 @@
 #
 # year-round base in the main continent
 # Dumont d'Urville, Île des Pétrels, -6640+14001, since 1956-11
-# <http://en.wikipedia.org/wiki/Dumont_d'Urville_Station> (2005-12-05)
+# <https://en.wikipedia.org/wiki/Dumont_d'Urville_Station> (2005-12-05)
 #
 # Another base at Port-Martin, 50km east, began operation in 1947.
 # It was destroyed by fire on 1952-01-14.
--- contrib/tzdata/asia.orig
+++ contrib/tzdata/asia
@@ -6,7 +6,7 @@
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
-# From Paul Eggert (2015-08-08):
+# From Paul Eggert (2017-01-13):
 #
 # Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
@@ -13,8 +13,8 @@
 # San Diego: ACS Publications, Inc. (2003).
 # Unfortunately this book contains many errors and cites no sources.
 #
-# Gwillim Law writes that a good source
-# for recent time zone data is the International Air Transport
+# Many years ago Gwillim Law wrote that a good source
+# for time zone data was the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
 # of the IATA's data after 1990.  Except where otherwise noted,
@@ -26,7 +26,7 @@
 #
 # For data circa 1899, a common source is:
 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
-# http://www.jstor.org/stable/1774359
+# https://www.jstor.org/stable/1774359
 #
 # For Russian data circa 1919, a source is:
 # Byalokoz EL. New Counting of Time in Russia since July 1, 1919.
@@ -35,29 +35,24 @@
 # A reliable and entertaining source about time zones is
 # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
 #
-# I invented the abbreviations marked '*' in the following table;
-# the rest are from earlier versions of this file, or from other sources.
-# Corrections are welcome!
+# The following alphabetic abbreviations appear in these tables:
 #	     std  dst
 #	     LMT	Local Mean Time
 #	2:00 EET  EEST	Eastern European Time
 #	2:00 IST  IDT	Israel
-#	3:00 AST  ADT	Arabia*
-#	3:30 IRST IRDT	Iran*
-#	4:00 GST	Gulf*
 #	5:30 IST	India
-#	7:00 ICT	Indochina, most times and locations*
 #	7:00 WIB	west Indonesia (Waktu Indonesia Barat)
 #	8:00 WITA	central Indonesia (Waktu Indonesia Tengah)
 #	8:00 CST	China
-#	8:00 IDT	Indochina, 1943-45, 1947-55, 1960-75 (some locations)*
-#	8:00 JWST	Western Standard Time (Japan, 1896/1937)*
-#	8:30 KST  KDT	Korea when at +0830*
-#	9:00 JCST	Central Standard Time (Japan, 1896/1937)
+#	8:30 KST  KDT	Korea when at +0830
 #	9:00 WIT	east Indonesia (Waktu Indonesia Timur)
 #	9:00 JST  JDT	Japan
 #	9:00 KST  KDT	Korea when at +09
 #	9:30 ACST	Australian Central Standard Time
+# Otherwise, these tables typically use numeric abbreviations like +03
+# and +0330 for integer hour and minute UTC offsets.  Although earlier
+# editions invented alphabetic time zone abbreviations for every
+# offset, this did not reflect common practice.
 #
 # See the 'europe' file for Russia and Turkey in Asia.
 
@@ -65,7 +60,7 @@
 # Incorporates data for Singapore from Robert Elz' asia 1.1, as well as
 # additional information from Tom Yap, Sun Microsystems Intercontinental
 # Technical Support (including a page from the Official Airline Guide -
-# Worldwide Edition).  The names for time zones are guesses.
+# Worldwide Edition).
 
 ###############################################################################
 
@@ -80,14 +75,14 @@
 Rule RussiaAsia	1981	1984	-	Apr	1	 0:00	1:00	S
 Rule RussiaAsia	1981	1983	-	Oct	1	 0:00	0	-
 Rule RussiaAsia	1984	1995	-	Sep	lastSun	 2:00s	0	-
-Rule RussiaAsia	1985	2011	-	Mar	lastSun	 2:00s	1:00	S
-Rule RussiaAsia	1996	2011	-	Oct	lastSun	 2:00s	0	-
+Rule RussiaAsia	1985	2010	-	Mar	lastSun	 2:00s	1:00	S
+Rule RussiaAsia	1996	2010	-	Oct	lastSun	 2:00s	0	-
 
 # Afghanistan
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Kabul	4:36:48 -	LMT	1890
-			4:00	-	AFT	1945
-			4:30	-	AFT
+			4:00	-	+04	1945
+			4:30	-	+0430
 
 # Armenia
 # From Paul Eggert (2006-03-22):
@@ -114,6 +109,9 @@
 # or
 # (brief)
 # http://www.worldtimezone.com/dst_news/dst_news_armenia03.html
+# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+Rule Armenia	2011	only	-	Mar	lastSun	 2:00s	1:00	S
+Rule Armenia	2011	only	-	Oct	lastSun	 2:00s	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Yerevan	2:58:00 -	LMT	1924 May  2
 			3:00	-	+03	1957 Mar
@@ -120,7 +118,8 @@
 			4:00 RussiaAsia +04/+05	1991 Mar 31  2:00s
 			3:00 RussiaAsia	+03/+04	1995 Sep 24  2:00s
 			4:00	-	+04	1997
-			4:00 RussiaAsia	+04/+05
+			4:00 RussiaAsia	+04/+05	2011
+			4:00	Armenia	+04/+05
 
 # Azerbaijan
 
@@ -132,7 +131,7 @@
 # From Steffen Thorsen (2016-03-17):
 # ... the Azerbaijani Cabinet of Ministers has cancelled switching to
 # daylight saving time....
-# http://www.azernews.az/azerbaijan/94137.html
+# https://www.azernews.az/azerbaijan/94137.html
 # http://vestnikkavkaza.net/news/Azerbaijani-Cabinet-of-Ministers-cancels-daylight-saving-time.html
 # http://en.apa.az/xeber_azerbaijan_abolishes_daylight_savings_ti_240862.html
 
@@ -173,11 +172,11 @@
 # the 19th and 20th, and they have not set the end date yet.
 #
 # Some sources:
-# http://in.reuters.com/article/southAsiaNews/idINIndia-40017620090601
+# https://in.reuters.com/article/southAsiaNews/idINIndia-40017620090601
 # http://bdnews24.com/details.php?id=85889&cid=2
 #
 # Our wrap-up:
-# http://www.timeanddate.com/news/time/bangladesh-daylight-saving-2009.html
+# https://www.timeanddate.com/news/time/bangladesh-daylight-saving-2009.html
 
 # From A. N. M. Kamrus Saadat (2009-06-15):
 # Finally we've got the official mail regarding DST start time where DST start
@@ -230,18 +229,17 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Dhaka	6:01:40 -	LMT	1890
 			5:53:20	-	HMT	1941 Oct    # Howrah Mean Time?
-			6:30	-	BURT	1942 May 15 # Burma Time
-			5:30	-	IST	1942 Sep
-			6:30	-	BURT	1951 Sep 30
-			6:00	-	DACT	1971 Mar 26 # Dacca Time
-			6:00	-	BDT	2009
-			6:00	Dhaka	BD%sT
+			6:30	-	+0630	1942 May 15
+			5:30	-	+0530	1942 Sep
+			6:30	-	+0630	1951 Sep 30
+			6:00	-	+06	2009
+			6:00	Dhaka	+06/+07
 
 # Bhutan
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Thimphu	5:58:36 -	LMT	1947 Aug 15 # or Thimbu
-			5:30	-	IST	1987 Oct
-			6:00	-	BTT	# Bhutan Time
+			5:30	-	+0530	1987 Oct
+			6:00	-	+06
 
 # British Indian Ocean Territory
 # Whitman and the 1995 CIA time zone map say 5:00, but the
@@ -251,25 +249,31 @@
 # then contained the Chagos Archipelago).
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Indian/Chagos	4:49:40	-	LMT	1907
-			5:00	-	IOT	1996 # BIOT Time
-			6:00	-	IOT
+			5:00	-	+05	1996
+			6:00	-	+06
 
 # Brunei
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Brunei	7:39:40 -	LMT	1926 Mar # Bandar Seri Begawan
-			7:30	-	BNT	1933
-			8:00	-	BNT
+			7:30	-	+0730	1933
+			8:00	-	+08
 
 # Burma / Myanmar
 
 # Milne says 6:24:40 was the meridian of the time ball observatory at Rangoon.
 
+# From Paul Eggert (2017-04-20):
+# Page 27 of Reed & Low (cited for Asia/Kolkata) says "Rangoon local time is
+# used upon the railways and telegraphs of Burma, and is 6h. 24m. 47s. ahead
+# of Greenwich."  This refers to the period before Burma's transition to +0630,
+# a transition for which Shanks is the only source.
+
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone	Asia/Yangon	6:24:40 -	LMT	1880        # or Rangoon
-			6:24:40	-	RMT	1920        # Rangoon Mean Time?
-			6:30	-	BURT	1942 May    # Burma Time
-			9:00	-	JST	1945 May  3
-			6:30	-	MMT	# Myanmar Time
+Zone	Asia/Yangon	6:24:47 -	LMT	1880        # or Rangoon
+			6:24:47	-	RMT	1920        # Rangoon local time
+			6:30	-	+0630	1942 May
+			9:00	-	+09	1945 May  3
+			6:30	-	+0630
 
 # Cambodia
 # See Asia/Bangkok.
@@ -323,7 +327,7 @@
 #
 # From Jesper Nørgaard Welen (2006-07-14):
 # I have investigated the timezones around 1970 on the
-# http://www.astro.com/atlas site [with provinces and county
+# https://www.astro.com/atlas site [with provinces and county
 # boundaries summarized below]....  A few other exceptions were two
 # counties on the Sichuan side of the Xizang-Sichuan border,
 # counties Dege and Baiyu which lies on the Sichuan side and are
@@ -332,7 +336,7 @@
 # (could be true), for the moment I am assuming that those two
 # counties are mistakes in the astro.com data.
 
-# From Paul Eggert (2014-06-30):
+# From Paul Eggert (2017-01-05):
 # Alois Treindl kindly sent me translations of the following two sources:
 #
 # (1)
@@ -390,28 +394,26 @@
 # mainly observed in coastal areas), the five zones were:
 #
 # Changbai Time ("Long-white Time", Long-white = Heilongjiang area) UT +08:30
-# Asia/Harbin (currently a link to Asia/Shanghai)
+# Now part of Asia/Shanghai; its pre-1970 times are not recorded here.
 # Heilongjiang (except Mohe county), Jilin
 #
 # Zhongyuan Time ("Central plain Time") UT +08
-# Asia/Shanghai
+# Now part of Asia/Shanghai.
 # most of China
-# This currently represents most other zones as well,
-# as apparently these regions have been the same since 1970.
 # Milne gives 8:05:43.2 for Xujiahui Observatory time; round to nearest.
 # Guo says Shanghai switched to UT +08 "from the end of the 19th century".
 #
-# Long-shu Time (probably due to Long and Shu being two names of the area) UT +07
-# Asia/Chongqing (currently a link to Asia/Shanghai)
+# Long-shu Time (probably as Long and Shu were two names of the area) UT +07
+# Now part of Asia/Shanghai; its pre-1970 times are not recorded here.
 # Guangxi, Guizhou, Hainan, Ningxia, Sichuan, Shaanxi, and Yunnan;
-# most of Gansu; west Inner Mongolia; west Qinghai; and the Guangdong
+# most of Gansu; west Inner Mongolia; east Qinghai; and the Guangdong
 # counties Deqing, Enping, Kaiping, Luoding, Taishan, Xinxing,
 # Yangchun, Yangjiang, Yu'nan, and Yunfu.
 #
 # Xin-zang Time ("Xinjiang-Tibet Time") UT +06
-# Asia/Urumqi
-# This currently represents Kunlun Time as well,
-# as apparently the two regions have been the same since 1970.
+# This region is now part of either Asia/Urumqi or Asia/Shanghai with
+# current boundaries uncertain; times before 1970 for areas that
+# disagree with Ürümqi or Shanghai are not recorded here.
 # The Gansu counties Aksay, Anxi, Dunhuang, Subei; west Qinghai;
 # the Guangdong counties  Xuwen, Haikang, Suixi, Lianjiang,
 # Zhanjiang, Wuchuan, Huazhou, Gaozhou, Maoming, Dianbai, and Xinyi;
@@ -422,7 +424,7 @@
 # Fukang, Kuitun, Kumukuli, Miquan, Qitai, and Turfan.
 #
 # Kunlun Time UT +05:30
-# Asia/Kashgar (currently a link to Asia/Urumqi)
+# This region is now in the same status as Xin-zang Time (see above).
 # West Tibet, including Pulan, Aheqi, Shufu, Shule;
 # West Xinjiang, including Aksu, Atushi, Yining, Hetian, Cele, Luopu, Nileke,
 # Zhaosu, Tekesi, Gongliu, Chabuchaer, Huocheng, Bole, Pishan, Suiding,
@@ -477,7 +479,7 @@
 
 # From David Cochrane (2014-03-26):
 # Just a confirmation that Ürümqi time was implemented in Ürümqi on 1 Feb 1986:
-# http://content.time.com/time/magazine/article/0,9171,960684,00.html
+# https://content.time.com/time/magazine/article/0,9171,960684,00.html
 
 # From Luther Ma (2014-04-22):
 # I have interviewed numerous people of various nationalities and from
@@ -523,7 +525,7 @@
 # Xinjiang time, used by many in western China; represented by Ürümqi / Ürümchi
 # / Wulumuqi.  (Please use Asia/Shanghai if you prefer Beijing time.)
 Zone	Asia/Urumqi	5:50:20	-	LMT	1928
-			6:00	-	XJT
+			6:00	-	+06
 
 
 # Hong Kong (Xianggang)
@@ -634,7 +636,7 @@
 # (both in Okinawa) adopt the Western Standard Time which is based on
 # 120E. The adoption began from Jan 1, 1896. The original text can be
 # found on Wikisource:
-# http://ja.wikisource.org/wiki/標準時ニ關スル件_(公布時)
+# https://ja.wikisource.org/wiki/標準時ニ關スル件_(公布時)
 # ... This could be the first adoption of time zone in Taiwan, because
 # during the Qing Dynasty, it seems that there was no time zone
 # declared officially.
@@ -647,7 +649,7 @@
 # territory, including later occupations, adopt Japan Central Time
 # (UTC+9). The adoption began on Oct 1, 1937. The original text can
 # be found on Wikisource:
-# http://ja.wikisource.org/wiki/明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件
+# https://ja.wikisource.org/wiki/明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件
 #
 # That is, the time zone of Taipei switched to UTC+9 on Oct 1, 1937.
 
@@ -742,30 +744,29 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 # Taipei or Taibei or T'ai-pei
 Zone	Asia/Taipei	8:06:00 -	LMT	1896 Jan  1
-			8:00	-	JWST	1937 Oct  1
+			8:00	-	CST	1937 Oct  1
 			9:00	-	JST	1945 Sep 21  1:00
 			8:00	Taiwan	C%sT
 
 # Macau (Macao, Aomen)
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Macau	1961	1962	-	Mar	Sun>=16	3:30	1:00	S
-Rule	Macau	1961	1964	-	Nov	Sun>=1	3:30	0	-
-Rule	Macau	1963	only	-	Mar	Sun>=16	0:00	1:00	S
-Rule	Macau	1964	only	-	Mar	Sun>=16	3:30	1:00	S
-Rule	Macau	1965	only	-	Mar	Sun>=16	0:00	1:00	S
-Rule	Macau	1965	only	-	Oct	31	0:00	0	-
-Rule	Macau	1966	1971	-	Apr	Sun>=16	3:30	1:00	S
-Rule	Macau	1966	1971	-	Oct	Sun>=16	3:30	0	-
-Rule	Macau	1972	1974	-	Apr	Sun>=15	0:00	1:00	S
-Rule	Macau	1972	1973	-	Oct	Sun>=15	0:00	0	-
-Rule	Macau	1974	1977	-	Oct	Sun>=15	3:30	0	-
-Rule	Macau	1975	1977	-	Apr	Sun>=15	3:30	1:00	S
-Rule	Macau	1978	1980	-	Apr	Sun>=15	0:00	1:00	S
-Rule	Macau	1978	1980	-	Oct	Sun>=15	0:00	0	-
+Rule	Macau	1961	1962	-	Mar	Sun>=16	3:30	1:00	D
+Rule	Macau	1961	1964	-	Nov	Sun>=1	3:30	0	S
+Rule	Macau	1963	only	-	Mar	Sun>=16	0:00	1:00	D
+Rule	Macau	1964	only	-	Mar	Sun>=16	3:30	1:00	D
+Rule	Macau	1965	only	-	Mar	Sun>=16	0:00	1:00	D
+Rule	Macau	1965	only	-	Oct	31	0:00	0	S
+Rule	Macau	1966	1971	-	Apr	Sun>=16	3:30	1:00	D
+Rule	Macau	1966	1971	-	Oct	Sun>=16	3:30	0	S
+Rule	Macau	1972	1974	-	Apr	Sun>=15	0:00	1:00	D
+Rule	Macau	1972	1973	-	Oct	Sun>=15	0:00	0	S
+Rule	Macau	1974	1977	-	Oct	Sun>=15	3:30	0	S
+Rule	Macau	1975	1977	-	Apr	Sun>=15	3:30	1:00	D
+Rule	Macau	1978	1980	-	Apr	Sun>=15	0:00	1:00	D
+Rule	Macau	1978	1980	-	Oct	Sun>=15	0:00	0	S
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Macau	7:34:20 -	LMT	1912 Jan  1
-			8:00	Macau	MO%sT	1999 Dec 20 # return to China
-			8:00	PRC	C%sT
+			8:00	Macau	C%sT
 
 
 ###############################################################################
@@ -784,6 +785,12 @@
 # Looks like the time zone split in Cyprus went through last night.
 # http://cyprus-mail.com/2016/10/30/cyprus-new-division-two-time-zones-now-reality/
 
+# From Paul Eggert (2017-10-18):
+# Northern Cyprus will reinstate winter time on October 29, thus
+# staying in sync with the rest of Cyprus.  See: Anastasiou A.
+# Cyprus to remain united in time.  Cyprus Mail 2017-10-17.
+# https://cyprus-mail.com/2017/10/17/cyprus-remain-united-time/
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Cyprus	1975	only	-	Apr	13	0:00	1:00	S
 Rule	Cyprus	1975	only	-	Oct	12	0:00	0	-
@@ -801,7 +808,8 @@
 Zone	Asia/Famagusta	2:15:48	-	LMT	1921 Nov 14
 			2:00	Cyprus	EE%sT	1998 Sep
 			2:00	EUAsia	EE%sT	2016 Sep  8
-			3:00	-	+03
+			3:00	-	+03	2017 Oct 29 1:00u
+			2:00	EUAsia	EE%sT
 
 # Classically, Cyprus belongs to Asia; e.g. see Herodotus, Histories, I.72.
 # However, for various reasons many users expect to find it under Europe.
@@ -861,7 +869,7 @@
 
 # From João Carrascalão, brother of the former governor of East Timor, in
 # East Timor may be late for its millennium
-# <http://etan.org/et99c/december/26-31/30ETMAY.htm> (1999-12-26/31):
+# <https://etan.org/et99c/december/26-31/30ETMAY.htm> (1999-12-26/31):
 # Portugal tried to change the time forward in 1974 because the sun
 # rises too early but the suggestion raised a lot of problems with the
 # Timorese and I still don't think it would work today because it
@@ -881,16 +889,15 @@
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Dili	8:22:20 -	LMT	1912 Jan  1
-			8:00	-	TLT	1942 Feb 21 23:00 # E Timor Time
-			9:00	-	JST	1945 Sep 23
-			9:00	-	TLT	1976 May  3
-			8:00	-	WITA	2000 Sep 17  0:00
-			9:00	-	TLT
+			8:00	-	+08	1942 Feb 21 23:00
+			9:00	-	+09	1976 May  3
+			8:00	-	+08	2000 Sep 17  0:00
+			9:00	-	+09
 
 # India
 
 # From Ian P. Beacock, in "A brief history of (modern) time", The Atlantic
-# http://www.theatlantic.com/technology/archive/2015/12/the-creation-of-modern-time/421419/
+# https://www.theatlantic.com/technology/archive/2015/12/the-creation-of-modern-time/421419/
 # (2015-12-22):
 # In January 1906, several thousand cotton-mill workers rioted on the
 # outskirts of Bombay....  They were protesting the proposed abolition of
@@ -897,14 +904,55 @@
 # local time in favor of Indian Standard Time....  Journalists called this
 # dispute the "Battle of the Clocks."  It lasted nearly half a century.
 
+# From Paul Eggert (2017-04-20):
+# Good luck trying to nail down old timekeeping records in India.
+# "... in the nineteenth century ... Madras Observatory took its magnetic
+# measurements on Göttingen time, its meteorological measurements on Madras
+# (local) time, dropped its time ball on Greenwich (ocean navigator's) time,
+# and distributed civil (local time)." -- Bartky IR. Selling the true time:
+# 19th-century timekeeping in america. Stanford U Press (2000), 247 note 19.
+# "A more potent cause of resistance to the general adoption of the present
+# standard time lies in the fact that it is Madras time.  The citizen of
+# Bombay, proud of being 'primus in Indis' and of Calcutta, equally proud of
+# his city being the Capital of India, and - for a part of the year - the Seat
+# of the Supreme Government, alike look down on Madras, and refuse to change
+# the time they are using, for that of what they regard as a benighted
+# Presidency; while Madras, having for long given the standard time to the
+# rest of India, would resist the adoption of any other Indian standard in its
+# place." -- Oldham RD. On Time in India: a suggestion for its improvement.
+# Proceedings of the Asiatic Society of Bengal (April 1899), 49-55.
+#
+# "In 1870 ... Madras time - 'now used by the telegraph and regulated from the
+# only government observatory' - was suggested as a standard railway time,
+# first to be adopted on the Great Indian Peninsular Railway (GIPR)....
+# Calcutta, Bombay, and Karachi, were to be allowed to continue with their
+# local time for civil purposes." - Prasad R. Tracks of Change: Railways and
+# Everyday Life in Colonial India. Cambridge University Press (2016), 145.
+#
+# Reed S, Low F. The Indian Year Book 1936-37. Bennett, Coleman, pp 27-8.
+# https://archive.org/details/in.ernet.dli.2015.282212
+# This lists +052110 as Madras local time used in railways, and says that on
+# 1906-01-01 railways and telegraphs in India switched to +0530.  Some
+# municipalities retained their former time, and the time in Calcutta
+# continued to depend on whether you were at the railway station or at
+# government offices.  Government time was at +055320 (according to Shanks) or
+# at +0554 (according to the Indian Year Book).  Railway time is more
+# appropriate for our purposes, as it was better documented, it is what we do
+# elsewhere (e.g., Europe/London before 1880), and after 1906 it was
+# consistent in the region now identified by Asia/Kolkata.  So, use railway
+# time for 1870-1941.  Shanks is our only (and dubious) source for the
+# 1941-1945 data.
+
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone	Asia/Kolkata	5:53:28 -	LMT	1880        # Kolkata
-			5:53:20	-	HMT	1941 Oct    # Howrah Mean Time?
-			6:30	-	BURT	1942 May 15 # Burma Time
+Zone	Asia/Kolkata	5:53:28 -	LMT	1854 Jun 28 # Kolkata
+			5:53:20	-	HMT	1870	    # Howrah Mean Time?
+			5:21:10	-	MMT	1906 Jan  1 # Madras local time
+			5:30	-	IST	1941 Oct
+			5:30	1:00	+0630	1942 May 15
 			5:30	-	IST	1942 Sep
-			5:30	1:00	IST	1945 Oct 15
+			5:30	1:00	+0630	1945 Oct 15
 			5:30	-	IST
-# The following are like Asia/Kolkata:
+# Since 1970 the following are like Asia/Kolkata:
 #	Andaman Is
 #	Lakshadweep (Laccadive, Minicoy and Amindivi Is)
 #	Nicobar Is
@@ -953,33 +1001,33 @@
 # Shanks & Pottenger say the next transition was at 1924 Jan 1 0:13,
 # but this must be a typo.
 			7:07:12	-	BMT	1923 Dec 31 23:47:12 # Batavia
-			7:20	-	JAVT	1932 Nov    # Java Time
-			7:30	-	WIB	1942 Mar 23
-			9:00	-	JST	1945 Sep 23
-			7:30	-	WIB	1948 May
-			8:00	-	WIB	1950 May
-			7:30	-	WIB	1964
+			7:20	-	+0720	1932 Nov
+			7:30	-	+0730	1942 Mar 23
+			9:00	-	+09	1945 Sep 23
+			7:30	-	+0730	1948 May
+			8:00	-	+08	1950 May
+			7:30	-	+0730	1964
 			7:00	-	WIB
 # west and central Borneo
 Zone Asia/Pontianak	7:17:20	-	LMT	1908 May
 			7:17:20	-	PMT	1932 Nov    # Pontianak MT
-			7:30	-	WIB	1942 Jan 29
-			9:00	-	JST	1945 Sep 23
-			7:30	-	WIB	1948 May
-			8:00	-	WIB	1950 May
-			7:30	-	WIB	1964
+			7:30	-	+0730	1942 Jan 29
+			9:00	-	+09	1945 Sep 23
+			7:30	-	+0730	1948 May
+			8:00	-	+08	1950 May
+			7:30	-	+0730	1964
 			8:00	-	WITA	1988 Jan  1
 			7:00	-	WIB
 # Sulawesi, Lesser Sundas, east and south Borneo
 Zone Asia/Makassar	7:57:36 -	LMT	1920
 			7:57:36	-	MMT	1932 Nov    # Macassar MT
-			8:00	-	WITA	1942 Feb  9
-			9:00	-	JST	1945 Sep 23
+			8:00	-	+08	1942 Feb  9
+			9:00	-	+09	1945 Sep 23
 			8:00	-	WITA
 # Maluku Islands, West Papua, Papua
 Zone Asia/Jayapura	9:22:48 -	LMT	1932 Nov
-			9:00	-	WIT	1944 Sep  1
-			9:30	-	ACST	1964
+			9:00	-	+09	1944 Sep  1
+			9:30	-	+0930	1964
 			9:00	-	WIT
 
 # Iran
@@ -1011,8 +1059,6 @@
 # for at least the last 5 years.  Before that, for a few years, the
 # date used was the first Thursday night of Farvardin and the last
 # Thursday night of Shahrivar, but I can't give exact dates....
-# I have also changed the abbreviations to what is considered correct
-# here in Iran, IRST for regular time and IRDT for daylight saving time.
 #
 # From Roozbeh Pournader (2005-04-05):
 # The text of the Iranian law, in effect since 1925, clearly mentions
@@ -1048,7 +1094,7 @@
 # From Reuters (2007-09-16), with a heads-up from Jesper Nørgaard Welen:
 # ... the Guardian Council ... approved a law on Sunday to re-introduce
 # daylight saving time ...
-# http://uk.reuters.com/article/oilRpt/idUKBLA65048420070916
+# https://uk.reuters.com/article/oilRpt/idUKBLA65048420070916
 #
 # From Roozbeh Pournader (2007-11-05):
 # This is quoted from Official Gazette of the Islamic Republic of
@@ -1119,9 +1165,9 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Tehran	3:25:44	-	LMT	1916
 			3:25:44	-	TMT	1946     # Tehran Mean Time
-			3:30	-	IRST	1977 Nov
-			4:00	Iran	IR%sT	1979
-			3:30	Iran	IR%sT
+			3:30	-	+0330	1977 Nov
+			4:00	Iran	+04/+05	1979
+			3:30	Iran	+0330/+0430
 
 
 # Iraq
@@ -1147,7 +1193,7 @@
 # http://www.aswataliraq.info/look/article.tpl?id=2047&IdLanguage=17&IdPublication=4&NrArticle=71743&NrIssue=1&NrSection=10
 #
 # We have published a short article in English about the change:
-# http://www.timeanddate.com/news/time/iraq-dumps-daylight-saving.html
+# https://www.timeanddate.com/news/time/iraq-dumps-daylight-saving.html
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Iraq	1982	only	-	May	1	0:00	1:00	D
@@ -1164,8 +1210,8 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Baghdad	2:57:40	-	LMT	1890
 			2:57:36	-	BMT	1918     # Baghdad Mean Time?
-			3:00	-	AST	1982 May
-			3:00	Iraq	A%sT
+			3:00	-	+03	1982 May
+			3:00	Iraq	+03/+04
 
 
 ###############################################################################
@@ -1455,17 +1501,15 @@
 # From Yu-Cheng Chuang (2013-07-12):
 # ...the Meiji Emperor announced Ordinance No. 167 of Meiji Year 28 "The clause
 # about standard time" ... The adoption began from Jan 1, 1896.
-# http://ja.wikisource.org/wiki/標準時ニ關スル件_(公布時)
+# https://ja.wikisource.org/wiki/標準時ニ關スル件_(公布時)
 #
 # ...the Showa Emperor announced Ordinance No. 529 of Showa Year 12 ... which
 # means the whole Japan territory, including later occupations, adopt Japan
 # Central Time (UTC+9). The adoption began on Oct 1, 1937.
-# http://ja.wikisource.org/wiki/明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件
+# https://ja.wikisource.org/wiki/明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Tokyo	9:18:59	-	LMT	1887 Dec 31 15:00u
-			9:00	-	JST	1896 Jan  1
-			9:00	-	JCST	1937 Oct  1
 			9:00	Japan	J%sT
 # Since 1938, all Japanese possessions have been like Asia/Tokyo.
 
@@ -1524,7 +1568,7 @@
 # Official, in Arabic:
 # http://www.petra.gov.jo/public_news/Nws_NewsDetails.aspx?Menu_ID=&Site_Id=2&lang=1&NewsID=133230&CatID=14
 # ... Our background/permalink about it
-# http://www.timeanddate.com/news/time/jordan-reverses-dst-decision.html
+# https://www.timeanddate.com/news/time/jordan-reverses-dst-decision.html
 # ...
 # http://www.petra.gov.jo/Public_News/Nws_NewsDetails.aspx?lang=2&site_id=1&NewsID=133313&Type=P
 # ... says midnight for the coming one and 1:00 for the ones in the future
@@ -1583,12 +1627,12 @@
 # was "blended" with the Central zone.  Therefore, Kazakhstan now has
 # two time zones, and difference between them is one hour.  The zone
 # closer to UTC is the former Western zone (probably still called the
-# same), encompassing four provinces in the west: Aqtobe, Atyrau,
-# Mangghystau, and West Kazakhstan.  The other zone encompasses
+# same), encompassing four provinces in the west: Aqtöbe, Atyraū,
+# Mangghystaū, and West Kazakhstan.  The other zone encompasses
 # everything else....  I guess that would make Kazakhstan time zones
 # de jure UTC+5 and UTC+6 respectively.
 
-# From Stepan Golosunov (2016-03-27) ([*] means see later comments below):
+# From Stepan Golosunov (2016-03-27):
 # Review of the linked documents from http://adilet.zan.kz/
 # produced the following data for post-1991 Kazakhstan:
 #
@@ -1634,7 +1678,7 @@
 #
 # This implies that on 1991-03-31 Asia/Oral remained on +04/+05 while
 # the rest of Kazakhstan switched from +06/+07 to +05/06 or from +05/06
-# to +04/+05. It's unclear how Kzyl-Orda oblast moved into the fifth
+# to +04/+05. It's unclear how Qyzylorda oblast moved into the fifth
 # time belt. (By switching from +04/+05 to +05/+06 on 1991-09-29?) ...
 #
 # 1. Act of the Cabinet of Ministers of the Republic of Kazakhstan
@@ -1647,18 +1691,18 @@
 # on the whole territory of Kazakhstan 1 hour forward on 1992-01-19 at
 # 2:00, specified DST rules.  It acknowledged that Kazakhstan was
 # located in the fourth and the fifth time belts and specified the
-# border between them to be located east of Kustanay and Aktyubinsk
-# oblasts (notably including Turgai and Kzyl-Orda oblasts into the fifth
+# border between them to be located east of Qostanay and Aktyubinsk
+# oblasts (notably including Turgai and Qyzylorda oblasts into the fifth
 # time belt).
 #
 # This means switch on 1992-01-19 at 2:00 from +04/+05 to +05/+06 for
-# Asia/Aqtau, Asia/Aqtobe, Asia/Oral, Atyrau and Kustanay oblasts; from
-# +05/+06 to +06/+07 for Asia/Almaty and Asia/Qyzylorda (and Arkalyk) [*]....
+# Asia/Aqtau, Asia/Aqtobe, Asia/Oral, Atyraū and Qostanay oblasts; from
+# +05/+06 to +06/+07 for Asia/Almaty and Asia/Qyzylorda (and Arkalyk)....
 #
 # 2. Act of the Cabinet of Ministers of the Republic of Kazakhstan
 # from 1992-03-27 No. 284
 # http://adilet.zan.kz/rus/docs/P920000284_
-# cancels extra hour ("decree time") for Uralsk and Kzyl-Orda oblasts
+# cancels extra hour ("decree time") for Uralsk and Qyzylorda oblasts
 # since the last Sunday of March 1992, while keeping them in the fourth
 # and the fifth time belts respectively.
 #
@@ -1665,7 +1709,7 @@
 # 3. Order of the Prime Minister of the Republic of Kazakhstan
 # from 1994-09-23 No. 384
 # http://adilet.zan.kz/rus/docs/R940000384_
-# cancels the extra hour ("decree time") on the territory of Mangystau
+# cancels the extra hour ("decree time") on the territory of Mangghystaū
 # oblast since the last Sunday of September 1994 (saying that time on
 # the territory would correspond to the third time belt as a
 # result)....
@@ -1679,15 +1723,12 @@
 # 5. Act of the Government of the Republic of Kazakhstan
 # from 1999-03-26 No. 305
 # http://adilet.zan.kz/rus/docs/P990000305_
-# cancels the extra hour ("decree time") for Atyrau oblast since the
+# cancels the extra hour ("decree time") for Atyraū oblast since the
 # last Sunday of March 1999 while retaining the oblast in the fourth
 # time belt.
 #
-# This means change from +05/+06 to +04/+05.
+# This means change from +05/+06 to +04/+05....
 #
-# There is no zone for Atyrau currently (listed under Asia/Aqtau in
-# zone1970.tab).[*]
-#
 # 6. Act of the Government of the Republic of Kazakhstan
 # from 2000-11-23 No. 1749
 # http://adilet.zan.kz/rus/archive/docs/P000001749_/23.11.2000
@@ -1696,10 +1737,10 @@
 # The only changes I noticed are in definition of the border between the
 # fourth and the fifth time belts.  They account for changes in spelling
 # and administrative division (splitting of Turgai oblast in 1997
-# probably changed time in territories incorporated into Kostanay oblast
-# (including Arkalyk) from +06/+07 to +05/+06) and move Kyzylorda oblast
+# probably changed time in territories incorporated into Qostanay oblast
+# (including Arkalyk) from +06/+07 to +05/+06) and move Qyzylorda oblast
 # from being in the fifth time belt and not using decree time into the
-# fourth time belt (no change in practice).[*]
+# fourth time belt (no change in practice).
 #
 # 7. Act of the Government of the Republic of Kazakhstan
 # from 2003-12-29 No. 1342
@@ -1709,7 +1750,7 @@
 # 8. Act of the Government of the Republic of Kazakhstan
 # from 2004-07-20 No. 775
 # http://adilet.zan.kz/rus/archive/docs/P040000775_/20.07.2004
-# modified the 2000-11-23 act to move Kostanay and Kyzylorda oblasts into
+# modified the 2000-11-23 act to move Qostanay and Qyzylorda oblasts into
 # the fifth time belt and add Aktobe oblast to the list of regions not
 # using extra hour ("decree time"), leaving Kazakhstan with only 2 time
 # zones (+04/+05 and +06/+07).  The changes were to be implemented
@@ -1721,14 +1762,14 @@
 # http://adilet.zan.kz/rus/docs/P040001059_
 # modified the 2000-11-23 act to remove exceptions from the "decree time"
 # (leaving Kazakhstan in +05/+06 and +06/+07 zones), amended the
-# 2004-07-20 act to implement changes for Atyrau, West Kazakhstan,
-# Kostanay, Kyzylorda and Mangystau oblasts by not moving clocks
-# during the 2014 transition to "winter" time.
+# 2004-07-20 act to implement changes for Atyraū, West Kazakhstan,
+# Qostanay, Qyzylorda and Mangghystaū oblasts by not moving clocks
+# during the 2004 transition to "winter" time.
 #
-# This means transition from +04/+05 to +05/+06 for Atyrau oblast (no
+# This means transition from +04/+05 to +05/+06 for Atyraū oblast (no
 # zone currently), Asia/Oral, Asia/Aqtau and transition from +05/+06 to
-# +06/+07 for Kostanay oblast (Kostanay and Arkalyk, no zones currently)
-# and Asia/Qyzylorda on 2004-10-31 at 3:00....[*]
+# +06/+07 for Qostanay oblast (Qostanay and Arkalyk, no zones currently)
+# and Asia/Qyzylorda on 2004-10-31 at 3:00....
 #
 # 10. Act of the Government of the Republic of Kazakhstan
 # from 2005-03-15 No. 231
@@ -1744,14 +1785,25 @@
 # Kazakh 1992-01-13 act appears to provide the same rules and 1992-03-27
 # act was to be enacted on the last Sunday of March 1992.
 
-# From Paul Eggert (2016-04-15):
-# The tables below should reflect Stepan Golosunov's remarks above,
-# except for the items marked "[*]" which I haven't gotten to yet.
-# It looks like we will need new zones Asia/Atyrau and Asia/Qostanay
-# to handle changes from 1992 through 2004 that we did not previously
-# know about.
+# From Stepan Golosunov (2016-11-08):
+# Turgai reorganization should affect only southern part of Qostanay
+# oblast.  Which should probably be separated into Asia/Arkalyk zone.
+# (There were also 1970, 1988 and 1990 Turgai oblast reorganizations
+# according to wikipedia.)
+#
+# [For Qostanay] http://www.ng.kz/gazeta/195/hranit/
+# suggests that clocks were to be moved 40 minutes backwards on
+# 1920-01-01 to the fourth time belt.  But I do not understand
+# how that could happen....
+#
+# [For Atyrau and Oral] 1919 decree
+# (http://www.worldtimezone.com/dst_news/dst_news_russia-1919-02-08.html
+# and in Byalokoz) lists Ural river (plus 10 versts on its left bank) in
+# the third time belt (before 1930 this means +03).
 
-#
+# From Paul Eggert (2016-12-06):
+# The tables below reflect Golosunov's remarks, with exceptions as noted.
+
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 #
 # Almaty (formerly Alma-Ata), representing most locations in Kazakhstan
@@ -1764,6 +1816,8 @@
 			6:00 RussiaAsia	+06/+07	2004 Oct 31  2:00s
 			6:00	-	+06
 # Qyzylorda (aka Kyzylorda, Kizilorda, Kzyl-Orda, etc.) (KZ-KZY)
+# This currently includes Qostanay (aka Kostanay, Kustanay) (KZ-KUS);
+# see comments below.
 Zone	Asia/Qyzylorda	4:21:52 -	LMT	1924 May  2
 			4:00	-	+04	1930 Jun 21
 			5:00	-	+05	1981 Apr  1
@@ -1775,7 +1829,21 @@
 			6:00 RussiaAsia	+06/+07	1992 Mar 29  2:00s
 			5:00 RussiaAsia	+05/+06	2004 Oct 31  2:00s
 			6:00	-	+06
-# Aqtobe (aka Aktobe, formerly Aktyubinsk) (KZ-AKT)
+# The following zone is like Asia/Qyzylorda except for being one
+# hour earlier from 1991-09-29 to 1992-03-29.  The 1991/2 rules for
+# Qostanay are unclear partly because of the 1997 Turgai
+# reorganization, so this zone is commented out for now.
+#Zone	Asia/Qostanay	4:14:20 -	LMT	1924 May  2
+#			4:00	-	+04	1930 Jun 21
+#			5:00	-	+05	1981 Apr  1
+#			5:00	1:00	+06	1981 Oct  1
+#			6:00	-	+06	1982 Apr  1
+#			5:00 RussiaAsia	+05/+06	1991 Mar 31  2:00s
+#			4:00 RussiaAsia	+04/+05	1992 Jan 19  2:00s
+#			5:00 RussiaAsia	+05/+06	2004 Oct 31  2:00s
+#			6:00	-	+06
+#
+# Aqtöbe (aka Aktobe, formerly Aktyubinsk) (KZ-AKT)
 Zone	Asia/Aqtobe	3:48:40	-	LMT	1924 May  2
 			4:00	-	+04	1930 Jun 21
 			5:00	-	+05	1981 Apr  1
@@ -1785,14 +1853,11 @@
 			4:00 RussiaAsia	+04/+05	1992 Jan 19  2:00s
 			5:00 RussiaAsia	+05/+06	2004 Oct 31  2:00s
 			5:00	-	+05
-# Qostanay (KZ-KUS)
-
-# Mangghystau (KZ-MAN)
+# Mangghystaū (KZ-MAN)
 # Aqtau was not founded until 1963, but it represents an inhabited region,
 # so include time stamps before 1963.
 Zone	Asia/Aqtau	3:21:04	-	LMT	1924 May  2
 			4:00	-	+04	1930 Jun 21
-			5:00	-	+05	1963
 			5:00	-	+05	1981 Oct  1
 			6:00	-	+06	1982 Apr  1
 			5:00 RussiaAsia	+05/+06	1991 Mar 31  2:00s
@@ -1800,12 +1865,22 @@
 			5:00 RussiaAsia	+05/+06	1994 Sep 25  2:00s
 			4:00 RussiaAsia	+04/+05	2004 Oct 31  2:00s
 			5:00	-	+05
-
+# Atyraū (KZ-ATY) is like Mangghystaū except it switched from
+# +04/+05 to +05/+06 in spring 1999, not fall 1994.
+Zone	Asia/Atyrau	3:27:44	-	LMT	1924 May  2
+			3:00	-	+03	1930 Jun 21
+			5:00	-	+05	1981 Oct  1
+			6:00	-	+06	1982 Apr  1
+			5:00 RussiaAsia	+05/+06	1991 Mar 31  2:00s
+			4:00 RussiaAsia	+04/+05	1992 Jan 19  2:00s
+			5:00 RussiaAsia	+05/+06	1999 Mar 28  2:00s
+			4:00 RussiaAsia	+04/+05	2004 Oct 31  2:00s
+			5:00	-	+05
 # West Kazakhstan (KZ-ZAP)
 # From Paul Eggert (2016-03-18):
 # The 1989 transition is from USSR act No. 227 (1989-03-14).
 Zone	Asia/Oral	3:25:24	-	LMT	1924 May  2 # or Ural'sk
-			4:00	-	+04	1930 Jun 21
+			3:00	-	+03	1930 Jun 21
 			5:00	-	+05	1981 Apr  1
 			5:00	1:00	+06	1981 Oct  1
 			6:00	-	+06	1982 Apr  1
@@ -1851,9 +1926,9 @@
 # between 1987 and 1988 ...
 
 # From Sanghyuk Jung (2014-10-29):
-# http://mm.icann.org/pipermail/tz/2014-October/021830.html
+# https://mm.icann.org/pipermail/tz/2014-October/021830.html
 # According to the Korean Wikipedia
-# http://ko.wikipedia.org/wiki/한국_표준시
+# https://ko.wikipedia.org/wiki/한국_표준시
 # [oldid=12896437 2014-09-04 08:03 UTC]
 # DST in Republic of Korea was as follows....  And I checked old
 # newspapers in Korean, all articles correspond with data in Wikipedia.
@@ -1911,7 +1986,6 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Seoul	8:27:52	-	LMT	1908 Apr  1
 			8:30	-	KST	1912 Jan  1
-			9:00	-	JCST	1937 Oct  1
 			9:00	-	JST	1945 Sep  8
 			9:00	-	KST	1954 Mar 21
 			8:30	ROK	K%sT	1961 Aug 10
@@ -1918,7 +1992,6 @@
 			9:00	ROK	K%sT
 Zone	Asia/Pyongyang	8:23:00 -	LMT	1908 Apr  1
 			8:30	-	KST	1912 Jan  1
-			9:00	-	JCST	1937 Oct  1
 			9:00	-	JST	1945 Aug 24
 			9:00	-	KST	2015 Aug 15 00:00
 			8:30	-	KST
@@ -1973,13 +2046,13 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Asia/Kuala_Lumpur	6:46:46 -	LMT	1901 Jan  1
 			6:55:25	-	SMT	1905 Jun  1 # Singapore M.T.
-			7:00	-	MALT	1933 Jan  1 # Malaya Time
-			7:00	0:20	MALST	1936 Jan  1
-			7:20	-	MALT	1941 Sep  1
-			7:30	-	MALT	1942 Feb 16
-			9:00	-	JST	1945 Sep 12
-			7:30	-	MALT	1982 Jan  1
-			8:00	-	MYT	# Malaysia Time
+			7:00	-	+07	1933 Jan  1
+			7:00	0:20	+0720	1936 Jan  1
+			7:20	-	+0720	1941 Sep  1
+			7:30	-	+0730	1942 Feb 16
+			9:00	-	+09	1945 Sep 12
+			7:30	-	+0730	1982 Jan  1
+			8:00	-	+08
 # Sabah & Sarawak
 # From Paul Eggert (2014-08-12):
 # The data entries here are mostly from Shanks & Pottenger, but the 1942, 1945
@@ -1986,17 +2059,16 @@
 # and 1982 transition dates are from Mok Ly Yng.
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Asia/Kuching	7:21:20	-	LMT	1926 Mar
-			7:30	-	BORT	1933        # Borneo Time
-			8:00	NBorneo	BOR%sT	1942 Feb 16
-			9:00	-	JST	1945 Sep 12
-			8:00	-	BORT	1982 Jan  1
-			8:00	-	MYT
+			7:30	-	+0730	1933
+			8:00 NBorneo  +08/+0820	1942 Feb 16
+			9:00	-	+09	1945 Sep 12
+			8:00	-	+08
 
 # Maldives
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Indian/Maldives	4:54:00 -	LMT	1880 # Male
 			4:54:00	-	MMT	1960 # Male Mean Time
-			5:00	-	MVT	# Maldives Time
+			5:00	-	+05
 
 # Mongolia
 
@@ -2078,7 +2150,7 @@
 # +08:00 instead. Different sources appear to disagree with the tz
 # database on this, e.g.:
 #
-# http://www.timeanddate.com/worldclock/city.html?n=1026
+# https://www.timeanddate.com/worldclock/city.html?n=1026
 # http://www.worldtimeserver.com/current_time_in_MN.aspx
 #
 # both say GMT+08:00.
@@ -2123,6 +2195,10 @@
 # correction of 02:00 (in the previous edition) not being done correctly
 # in the latest edition; so ignore it for now.
 
+# From Ganbold Tsagaankhuu (2017-02-09):
+# Mongolian Government meeting has concluded today to cancel daylight
+# saving time adoption in Mongolia.  Source: http://zasag.mn/news/view/16192
+
 Rule	Mongol	1985	1998	-	Mar	lastSun	0:00	1:00	S
 Rule	Mongol	1984	1998	-	Sep	lastSun	0:00	0	-
 # IATA SSIM (1999-09) says Mongolia no longer observes DST.
@@ -2129,31 +2205,31 @@
 Rule	Mongol	2001	only	-	Apr	lastSat	2:00	1:00	S
 Rule	Mongol	2001	2006	-	Sep	lastSat	2:00	0	-
 Rule	Mongol	2002	2006	-	Mar	lastSat	2:00	1:00	S
-Rule	Mongol	2015	max	-	Mar	lastSat	2:00	1:00	S
-Rule	Mongol	2015	max	-	Sep	lastSat	0:00	0	-
+Rule	Mongol	2015	2016	-	Mar	lastSat	2:00	1:00	S
+Rule	Mongol	2015	2016	-	Sep	lastSat	0:00	0	-
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 # Hovd, a.k.a. Chovd, Dund-Us, Dzhargalant, Khovd, Jirgalanta
 Zone	Asia/Hovd	6:06:36 -	LMT	1905 Aug
-			6:00	-	HOVT	1978     # Hovd Time
-			7:00	Mongol	HOV%sT
+			6:00	-	+06	1978
+			7:00	Mongol	+07/+08
 # Ulaanbaatar, a.k.a. Ulan Bataar, Ulan Bator, Urga
 Zone	Asia/Ulaanbaatar 7:07:32 -	LMT	1905 Aug
-			7:00	-	ULAT	1978     # Ulaanbaatar Time
-			8:00	Mongol	ULA%sT
+			7:00	-	+07	1978
+			8:00	Mongol	+08/+09
 # Choibalsan, a.k.a. Bajan Tümen, Bajan Tumen, Chojbalsan,
 # Choybalsan, Sanbejse, Tchoibalsan
 Zone	Asia/Choibalsan	7:38:00 -	LMT	1905 Aug
-			7:00	-	ULAT	1978
-			8:00	-	ULAT	1983 Apr
-			9:00	Mongol	CHO%sT	2008 Mar 31 # Choibalsan Time
-			8:00	Mongol	CHO%sT
+			7:00	-	+07	1978
+			8:00	-	+08	1983 Apr
+			9:00	Mongol	+09/+10	2008 Mar 31
+			8:00	Mongol	+08/+09
 
 # Nepal
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Kathmandu	5:41:16 -	LMT	1920
-			5:30	-	IST	1986
-			5:45	-	NPT	# Nepal Time
+			5:30	-	+0530	1986
+			5:45	-	+0545
 
 # Oman
 # See Asia/Dubai.
@@ -2204,7 +2280,7 @@
 # help reduce load shedding by approving the closure of commercial centres at
 # 9pm and moving clocks forward by one hour for the next three months. ...."
 #
-# http://www.worldtimezone.net/dst_news/dst_news_pakistan01.html
+# http://www.worldtimezone.com/dst_news/dst_news_pakistan01.html
 # http://www.dailytimes.com.pk/default.asp?page=2008%5C05%5C15%5Cstory_15-5-2008_pg1_4
 
 # From Arthur David Olson (2008-05-19):
@@ -2270,7 +2346,7 @@
 #
 # We have confirmed this year's end date with both with the Ministry of
 # Water and Power and the Pakistan Electric Power Company:
-# http://www.timeanddate.com/news/time/pakistan-ends-dst09.html
+# https://www.timeanddate.com/news/time/pakistan-ends-dst09.html
 
 # From Christoph Göhre (2009-10-01):
 # [T]he German Consulate General in Karachi reported me today that Pakistan
@@ -2302,10 +2378,10 @@
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Karachi	4:28:12 -	LMT	1907
-			5:30	-	IST	1942 Sep
-			5:30	1:00	IST	1945 Oct 15
-			5:30	-	IST	1951 Sep 30
-			5:00	-	KART	1971 Mar 26 # Karachi Time
+			5:30	-	+0530	1942 Sep
+			5:30	1:00	+0630	1945 Oct 15
+			5:30	-	+0530	1951 Sep 30
+			5:00	-	+05	1971 Mar 26
 			5:00 Pakistan	PK%sT	# Pakistan Time
 
 # Palestine
@@ -2452,7 +2528,7 @@
 #
 # We are not sure if Gaza will do the same, last year they had a different
 # end date, we will keep this page updated:
-# http://www.timeanddate.com/news/time/westbank-gaza-dst-2009.html
+# https://www.timeanddate.com/news/time/westbank-gaza-dst-2009.html
 
 # From Alexander Krivenyshev (2009-09-02):
 # Seems that Gaza Strip will go back to Winter Time same date as West Bank.
@@ -2490,7 +2566,7 @@
 # the clocks were set back one hour at 2010-08-11 00:00:00 local time in
 # Gaza and the West Bank.
 # Some more background info:
-# http://www.timeanddate.com/news/time/westbank-gaza-end-dst-2010.html
+# https://www.timeanddate.com/news/time/westbank-gaza-end-dst-2010.html
 
 # From Steffen Thorsen (2011-08-26):
 # Gaza and the West Bank did go back to standard time in the beginning of
@@ -2500,7 +2576,7 @@
 #
 # http://www.maannews.net/eng/ViewDetails.aspx?ID=416217
 # Additional info:
-# http://www.timeanddate.com/news/time/palestine-dst-2011.html
+# https://www.timeanddate.com/news/time/palestine-dst-2011.html
 
 # From Alexander Krivenyshev (2011-08-27):
 # According to the article in The Jerusalem Post:
@@ -2510,7 +2586,7 @@
 # The Hamas government said on Saturday that it won't observe summertime after
 # the Muslim feast of Id al-Fitr, which begins on Tuesday..."
 # ...
-# http://www.jpost.com/MiddleEast/Article.aspx?id=235650
+# https://www.jpost.com/MiddleEast/Article.aspx?id=235650
 # http://www.worldtimezone.com/dst_news/dst_news_gazastrip05.html
 # The rules for Egypt are stolen from the 'africa' file.
 
@@ -2531,7 +2607,7 @@
 # http://safa.ps/details/news/74352/%D8%A8%D8%AF%D8%A1-%D8%A7%D9%84%D8%AA%D9%88%D9%82%D9%8A%D8%AA-%D8%A7%D9%84%D8%B5%D9%8A%D9%81%D9%8A-%D8%A8%D8%A7%D9%84%D8%B6%D9%81%D8%A9-%D9%88%D8%BA%D8%B2%D8%A9-%D9%84%D9%8A%D9%84%D8%A9-%D8%A7%D9%84%D8%AC%D9%85%D8%B9%D8%A9.html
 #
 # Our brief summary:
-# http://www.timeanddate.com/news/time/gaza-west-bank-dst-2012.html
+# https://www.timeanddate.com/news/time/gaza-west-bank-dst-2012.html
 
 # From Steffen Thorsen (2013-03-26):
 # The following news sources tells that Palestine will "start daylight saving
@@ -2551,11 +2627,11 @@
 
 # From Steffen Thorsen (2015-03-03):
 # Sources such as http://www.alquds.com/news/article/view/id/548257
-# and http://www.raya.ps/ar/news/890705.html say Palestine areas will
+# and https://www.raya.ps/ar/news/890705.html say Palestine areas will
 # start DST on 2015-03-28 00:00 which is one day later than expected.
 #
 # From Paul Eggert (2015-03-03):
-# http://www.timeanddate.com/time/change/west-bank/ramallah?year=2014
+# https://www.timeanddate.com/time/change/west-bank/ramallah?year=2014
 # says that the fall 2014 transition was Oct 23 at 24:00.
 
 # From Hannah Kreitem (2016-03-09):
@@ -2579,8 +2655,8 @@
 #
 # From Paul Eggert (2016-10-19):
 # It's also consistent with predictions in the following URLs today:
-# http://www.timeanddate.com/time/change/gaza-strip/gaza
-# http://www.timeanddate.com/time/change/west-bank/hebron
+# https://www.timeanddate.com/time/change/gaza-strip/gaza
+# https://www.timeanddate.com/time/change/west-bank/hebron
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule EgyptAsia	1957	only	-	May	10	0:00	1:00	S
@@ -2616,7 +2692,7 @@
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Gaza	2:17:52	-	LMT	1900 Oct
-			2:00	Zion	EET	1948 May 15
+			2:00	Zion	EET/EEST 1948 May 15
 			2:00 EgyptAsia	EE%sT	1967 Jun  5
 			2:00	Zion	I%sT	1996
 			2:00	Jordan	EE%sT	1999
@@ -2629,7 +2705,7 @@
 			2:00 Palestine	EE%sT
 
 Zone	Asia/Hebron	2:20:23	-	LMT	1900 Oct
-			2:00	Zion	EET	1948 May 15
+			2:00	Zion	EET/EEST 1948 May 15
 			2:00 EgyptAsia	EE%sT	1967 Jun  5
 			2:00	Zion	I%sT	1996
 			2:00	Jordan	EE%sT	1999
@@ -2643,7 +2719,7 @@
 # Philippines, issued a proclamation announcing that 1844-12-30 was to
 # be immediately followed by 1845-01-01; see R.H. van Gent's
 # History of the International Date Line
-# http://www.staff.science.uu.nl/~gent0113/idl/idl_philippines.htm
+# https://www.staff.science.uu.nl/~gent0113/idl/idl_philippines.htm
 # The rest of the data entries are from Shanks & Pottenger.
 
 # From Jesper Nørgaard Welen (2006-04-26):
@@ -2670,15 +2746,15 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Manila	-15:56:00 -	LMT	1844 Dec 31
 			8:04:00 -	LMT	1899 May 11
-			8:00	Phil	PH%sT	1942 May
-			9:00	-	JST	1944 Nov
-			8:00	Phil	PH%sT
+			8:00	Phil	+08/+09	1942 May
+			9:00	-	+09	1944 Nov
+			8:00	Phil	+08/+09
 
 # Qatar
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Qatar	3:26:08 -	LMT	1920     # Al Dawhah / Doha
-			4:00	-	GST	1972 Jun
-			3:00	-	AST
+			4:00	-	+04	1972 Jun
+			3:00	-	+03
 Link Asia/Qatar Asia/Bahrain
 
 # Saudi Arabia
@@ -2705,7 +2781,7 @@
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Riyadh	3:06:52 -	LMT	1947 Mar 14
-			3:00	-	AST
+			3:00	-	+03
 Link Asia/Riyadh Asia/Aden	# Yemen
 Link Asia/Riyadh Asia/Kuwait
 
@@ -2715,14 +2791,13 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Singapore	6:55:25 -	LMT	1901 Jan  1
 			6:55:25	-	SMT	1905 Jun  1 # Singapore M.T.
-			7:00	-	MALT	1933 Jan  1 # Malaya Time
-			7:00	0:20	MALST	1936 Jan  1
-			7:20	-	MALT	1941 Sep  1
-			7:30	-	MALT	1942 Feb 16
-			9:00	-	JST	1945 Sep 12
-			7:30	-	MALT	1965 Aug  9 # independence
-			7:30	-	SGT	1982 Jan  1 # Singapore Time
-			8:00	-	SGT
+			7:00	-	+07	1933 Jan  1
+			7:00	0:20	+0720	1936 Jan  1
+			7:20	-	+0720	1941 Sep  1
+			7:30	-	+0730	1942 Feb 16
+			9:00	-	+09	1945 Sep 12
+			7:30	-	+0730	1982 Jan  1
+			8:00	-	+08
 
 # Spratly Is
 # no information
@@ -2781,8 +2856,8 @@
 Zone	Asia/Colombo	5:19:24 -	LMT	1880
 			5:19:32	-	MMT	1906        # Moratuwa Mean Time
 			5:30	-	+0530	1942 Jan  5
-			5:30	0:30	+0530/+06 1942 Sep
-			5:30	1:00	+0530/+0630 1945 Oct 16  2:00
+			5:30	0:30	+06	1942 Sep
+			5:30	1:00	+0630	1945 Oct 16  2:00
 			5:30	-	+0530	1996 May 25  0:00
 			6:30	-	+0630	1996 Oct 26  0:30
 			6:00	-	+06	2006 Apr 15  0:30
@@ -2908,7 +2983,7 @@
 # We have not found any sources saying anything about when DST ends this year.
 #
 # Our summary
-# http://www.timeanddate.com/news/time/syria-dst-starts-march-27-2009.html
+# https://www.timeanddate.com/news/time/syria-dst-starts-march-27-2009.html
 
 # From Steffen Thorsen (2009-10-27):
 # The Syrian Arab News Network on 2009-09-29 reported that Syria will
@@ -2935,7 +3010,7 @@
 # http://www.sana.sy/ara/2/2012/03/26/408215.htm
 #
 # Our brief summary:
-# http://www.timeanddate.com/news/time/syria-dst-2012.html
+# https://www.timeanddate.com/news/time/syria-dst-2012.html
 
 # From Arthur David Olson (2012-03-27):
 # Assume last Friday in March going forward XXX.
@@ -2964,7 +3039,7 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Bangkok	6:42:04	-	LMT	1880
 			6:42:04	-	BMT	1920 Apr # Bangkok Mean Time
-			7:00	-	ICT
+			7:00	-	+07
 Link Asia/Bangkok Asia/Phnom_Penh	# Cambodia
 Link Asia/Bangkok Asia/Vientiane	# Laos
 
@@ -2980,7 +3055,7 @@
 # United Arab Emirates
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Dubai	3:41:12 -	LMT	1920
-			4:00	-	GST
+			4:00	-	+04
 Link Asia/Dubai Asia/Muscat	# Oman
 
 # Uzbekistan
@@ -3018,7 +3093,7 @@
 # is quoted verbatim in:
 # http://www.thoigian.com.vn/?mPage=P80D01
 # is translated by Brian Inglis in:
-# http://mm.icann.org/pipermail/tz/2014-October/021654.html
+# https://mm.icann.org/pipermail/tz/2014-October/021654.html
 # and is the basis for the information below.
 #
 # The 1906 transition was effective July 1 and standardized Indochina to
@@ -3053,15 +3128,15 @@
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Asia/Ho_Chi_Minh	7:06:40 -	LMT	1906 Jul  1
-			7:06:30	-	PLMT	1911 May  1
-			7:00	-	ICT	1942 Dec 31 23:00
-			8:00	-	IDT	1945 Mar 14 23:00
-			9:00	-	JST	1945 Sep  2
-			7:00	-	ICT	1947 Apr  1
-			8:00	-	IDT	1955 Jul  1
-			7:00	-	ICT	1959 Dec 31 23:00
-			8:00	-	IDT	1975 Jun 13
-			7:00	-	ICT
+			7:06:30	-	PLMT	1911 May  1 # Phù Liễn MT
+			7:00	-	+07	1942 Dec 31 23:00
+			8:00	-	+08	1945 Mar 14 23:00
+			9:00	-	+09	1945 Sep  2
+			7:00	-	+07	1947 Apr  1
+			8:00	-	+08	1955 Jul  1
+			7:00	-	+07	1959 Dec 31 23:00
+			8:00	-	+08	1975 Jun 13
+			7:00	-	+07
 
 # Yemen
 # See Asia/Riyadh.
--- contrib/tzdata/australasia.orig
+++ contrib/tzdata/australasia
@@ -44,8 +44,8 @@
 			 8:00	Aus	AW%sT	1943 Jul
 			 8:00	AW	AW%sT
 Zone Australia/Eucla	 8:35:28 -	LMT	1895 Dec
-			 8:45	Aus	ACW%sT	1943 Jul
-			 8:45	AW	ACW%sT
+			 8:45	Aus +0845/+0945	1943 Jul
+			 8:45	AW  +0845/+0945
 
 # Queensland
 #
@@ -212,7 +212,8 @@
 Rule	LH	2008	max	-	Oct	Sun>=1	2:00	0:30	D
 Zone Australia/Lord_Howe 10:36:20 -	LMT	1895 Feb
 			10:00	-	AEST	1981 Mar
-			10:30	LH	LH%sT
+			10:30	LH	+1030/+1130 1985 Jul
+			10:30	LH	+1030/+11
 
 # Australian miscellany
 #
@@ -250,12 +251,12 @@
 			0	-	-00	1948 Mar 25
 			10:00	Aus	AE%sT	1967
 			10:00	AT	AE%sT	2010 Apr  4  3:00
-			11:00	-	MIST	# Macquarie I Standard Time
+			11:00	-	+11
 
 # Christmas
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Indian/Christmas	7:02:52 -	LMT	1895 Feb
-			7:00	-	CXT	# Christmas Island Time
+			7:00	-	+07
 
 # Cocos (Keeling) Is
 # These islands were ruled by the Ross family from about 1830 to 1978.
@@ -262,7 +263,7 @@
 # We don't know when standard time was introduced; for now, we guess 1900.
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Indian/Cocos	6:27:40	-	LMT	1900
-			6:30	-	CCT	# Cocos Islands Time
+			6:30	-	+0630
 
 
 # Fiji
@@ -292,7 +293,7 @@
 # http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=1096:3310-cabinet-approves-change-in-daylight-savings-dates&catid=49:cabinet-releases&Itemid=166
 #
 # A bit more background info here:
-# http://www.timeanddate.com/news/time/fiji-dst-ends-march-2010.html
+# https://www.timeanddate.com/news/time/fiji-dst-ends-march-2010.html
 
 # From Alexander Krivenyshev (2010-10-24):
 # According to Radio Fiji and Fiji Times online, Fiji will end DST 3
@@ -356,9 +357,12 @@
 # clocks go forward an hour at 2am to 3am....  Daylight Saving will
 # end at 3.00am on Sunday 15th January 2017."
 
-# From Paul Eggert (2016-10-03):
-# For now, guess DST from 02:00 the first Sunday in November to
-# 03:00 the third Sunday in January.  Although ad hoc, it matches
+# From Paul Eggert (2017-08-21):
+# Dominic Fok writes (2017-08-20) that DST ends 2018-01-14, citing
+# Extraordinary Government of Fiji Gazette Supplement No. 21 (2017-08-27),
+# [Legal Notice No. 41] of an order of the previous day by J Usamate.
+# For now, guess DST from 02:00 the first Sunday in November to 03:00
+# the first Sunday on or after January 14.  Although ad hoc, it matches
 # transitions since late 2014 and seems more likely to match future
 # practice than guessing no DST.
 
@@ -372,19 +376,19 @@
 Rule	Fiji	2012	2013	-	Jan	Sun>=18	3:00	0	-
 Rule	Fiji	2014	only	-	Jan	Sun>=18	2:00	0	-
 Rule	Fiji	2014	max	-	Nov	Sun>=1	2:00	1:00	S
-Rule	Fiji	2015	max	-	Jan	Sun>=15	3:00	0	-
+Rule	Fiji	2015	max	-	Jan	Sun>=14	3:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Fiji	11:55:44 -	LMT	1915 Oct 26 # Suva
-			12:00	Fiji	FJ%sT	# Fiji Time
+			12:00	Fiji	+12/+13
 
 # French Polynesia
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Gambier	 -8:59:48 -	LMT	1912 Oct # Rikitea
-			 -9:00	-	GAMT	# Gambier Time
+			 -9:00	-	-09
 Zone	Pacific/Marquesas -9:18:00 -	LMT	1912 Oct
-			 -9:30	-	MART	# Marquesas Time
+			 -9:30	-	-0930
 Zone	Pacific/Tahiti	 -9:58:16 -	LMT	1912 Oct # Papeete
-			-10:00	-	TAHT	# Tahiti Time
+			-10:00	-	-10
 # Clipperton (near North America) is administered from French Polynesia;
 # it is uninhabited.
 
@@ -399,15 +403,15 @@
 # Kiribati
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Tarawa	 11:32:04 -	LMT	1901 # Bairiki
-			 12:00	-	GILT	# Gilbert Is Time
+			 12:00	-	+12
 Zone Pacific/Enderbury	-11:24:20 -	LMT	1901
-			-12:00	-	PHOT	1979 Oct # Phoenix Is Time
-			-11:00	-	PHOT	1995
-			 13:00	-	PHOT
+			-12:00	-	-12	1979 Oct
+			-11:00	-	-11	1995
+			 13:00	-	+13
 Zone Pacific/Kiritimati	-10:29:20 -	LMT	1901
-			-10:40	-	LINT	1979 Oct # Line Is Time
-			-10:00	-	LINT	1995
-			 14:00	-	LINT
+			-10:40	-	-1040	1979 Oct
+			-10:00	-	-10	1995
+			 14:00	-	+14
 
 # N Mariana Is
 # See Pacific/Guam.
@@ -415,31 +419,31 @@
 # Marshall Is
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Majuro	11:24:48 -	LMT	1901
-			11:00	-	MHT	1969 Oct # Marshall Islands Time
-			12:00	-	MHT
+			11:00	-	+11	1969 Oct
+			12:00	-	+12
 Zone Pacific/Kwajalein	11:09:20 -	LMT	1901
-			11:00	-	MHT	1969 Oct
-			-12:00	-	KWAT	1993 Aug 20 # Kwajalein Time
-			12:00	-	MHT
+			11:00	-	+11	1969 Oct
+			-12:00	-	-12	1993 Aug 20
+			12:00	-	+12
 
 # Micronesia
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Chuuk	10:07:08 -	LMT	1901
-			10:00	-	CHUT	# Chuuk Time
+			10:00	-	+10
 Zone Pacific/Pohnpei	10:32:52 -	LMT	1901 # Kolonia
-			11:00	-	PONT	# Pohnpei Time
+			11:00	-	+11
 Zone Pacific/Kosrae	10:51:56 -	LMT	1901
-			11:00	-	KOST	1969 Oct # Kosrae Time
-			12:00	-	KOST	1999
-			11:00	-	KOST
+			11:00	-	+11	1969 Oct
+			12:00	-	+12	1999
+			11:00	-	+11
 
 # Nauru
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Nauru	11:07:40 -	LMT	1921 Jan 15 # Uaobe
-			11:30	-	NRT	1942 Mar 15 # Nauru Time
-			9:00	-	JST	1944 Aug 15
-			11:30	-	NRT	1979 May
-			12:00	-	NRT
+			11:30	-	+1130	1942 Mar 15
+			9:00	-	+09	1944 Aug 15
+			11:30	-	+1130	1979 May
+			12:00	-	+12
 
 # New Caledonia
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
@@ -450,7 +454,7 @@
 Rule	NC	1997	only	-	Mar	 2	2:00s	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Noumea	11:05:48 -	LMT	1912 Jan 13 # Nouméa
-			11:00	NC	NC%sT
+			11:00	NC	+11/+12
 
 
 ###############################################################################
@@ -491,8 +495,8 @@
 			11:30	NZ	NZ%sT	1946 Jan  1
 			12:00	NZ	NZ%sT
 Zone Pacific/Chatham	12:13:48 -	LMT	1868 Nov  2
-			12:15	-	CHAST	1946 Jan  1
-			12:45	Chatham	CHA%sT
+			12:15	-	+1215	1946 Jan  1
+			12:45	Chatham	+1245/+1345
 
 Link Pacific/Auckland Antarctica/McMurdo
 
@@ -514,8 +518,8 @@
 Rule	Cook	1979	1990	-	Oct	lastSun	0:00	0:30	HS
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Rarotonga	-10:39:04 -	LMT	1901        # Avarua
-			-10:30	-	CKT	1978 Nov 12 # Cook Is Time
-			-10:00	Cook	CK%sT
+			-10:30	-	-1030	1978 Nov 12
+			-10:00	Cook	-10/-0930
 
 ###############################################################################
 
@@ -523,29 +527,29 @@
 # Niue
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Niue	-11:19:40 -	LMT	1901        # Alofi
-			-11:20	-	NUT	1951        # Niue Time
-			-11:30	-	NUT	1978 Oct  1
-			-11:00	-	NUT
+			-11:20	-	-1120	1951
+			-11:30	-	-1130	1978 Oct  1
+			-11:00	-	-11
 
 # Norfolk
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Norfolk	11:11:52 -	LMT	1901 # Kingston
-			11:12	-	NMT	1951 # Norfolk Mean Time
-			11:30	-	NFT	1974 Oct 27 02:00 # Norfolk T.
-			11:30	1:00	NFST	1975 Mar  2 02:00
-			11:30	-	NFT	2015 Oct  4 02:00
-			11:00	-	NFT
+			11:12	-	+1112	1951
+			11:30	-	+1130	1974 Oct 27 02:00
+			11:30	1:00	+1230	1975 Mar  2 02:00
+			11:30	-	+1130	2015 Oct  4 02:00
+			11:00	-	+11
 
 # Palau (Belau)
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Palau	8:57:56 -	LMT	1901 # Koror
-			9:00	-	PWT	# Palau Time
+			9:00	-	+09
 
 # Papua New Guinea
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Port_Moresby 9:48:40 -	LMT	1880
 			9:48:32	-	PMMT	1895 # Port Moresby Mean Time
-			10:00	-	PGT	# Papua New Guinea Time
+			10:00	-	+10
 #
 # From Paul Eggert (2014-10-13):
 # Base the Bougainville entry on the Arawa-Kieta region, which appears to have
@@ -556,32 +560,30 @@
 # The World War II entries below are instead based on Arawa-Kieta.
 # The Japanese occupied Kieta in July 1942,
 # according to the Pacific War Online Encyclopedia
-# http://pwencycl.kgbudge.com/B/o/Bougainville.htm
+# https://pwencycl.kgbudge.com/B/o/Bougainville.htm
 # and seem to have controlled it until their 1945-08-21 surrender.
 #
 # The Autonomous Region of Bougainville switched from UT +10 to +11
-# on 2014-12-28 at 02:00.  They call +11 "Bougainville Standard Time";
-# abbreviate this as BST.  See:
+# on 2014-12-28 at 02:00.  They call +11 "Bougainville Standard Time".
+# See:
 # http://www.bougainville24.com/bougainville-issues/bougainville-gets-own-timezone/
 #
 Zone Pacific/Bougainville 10:22:16 -	LMT	1880
 			 9:48:32 -	PMMT	1895
-			10:00	-	PGT	1942 Jul
-			 9:00	-	JST	1945 Aug 21
-			10:00	-	PGT	2014 Dec 28  2:00
-			11:00	-	BST
+			10:00	-	+10	1942 Jul
+			 9:00	-	+09	1945 Aug 21
+			10:00	-	+10	2014 Dec 28  2:00
+			11:00	-	+11
 
 # Pitcairn
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Pitcairn	-8:40:20 -	LMT	1901        # Adamstown
-			-8:30	-	PNT	1998 Apr 27  0:00
-			-8:00	-	PST	# Pitcairn Standard Time
+			-8:30	-	-0830	1998 Apr 27  0:00
+			-8:00	-	-08
 
 # American Samoa
-Zone Pacific/Pago_Pago	 12:37:12 -	LMT	1879 Jul  5
+Zone Pacific/Pago_Pago	 12:37:12 -	LMT	1892 Jul  5
 			-11:22:48 -	LMT	1911
-			-11:00	-	NST	1967 Apr    # N=Nome
-			-11:00	-	BST	1983 Nov 30 # B=Bering
 			-11:00	-	SST	            # S=Samoa
 Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands
 
@@ -596,7 +598,7 @@
 # Sunday of April 2011."
 #
 # Background info:
-# http://www.timeanddate.com/news/time/samoa-dst-plan-2009.html
+# https://www.timeanddate.com/news/time/samoa-dst-plan-2009.html
 #
 # Samoa's Daylight Saving Time Act 2009 is available here, but does not
 # contain any dates:
@@ -660,19 +662,19 @@
 Rule	WS	2012	max	-	Apr	Sun>=1	4:00	0	S
 Rule	WS	2012	max	-	Sep	lastSun	3:00	1	D
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone Pacific/Apia	 12:33:04 -	LMT	1879 Jul  5
+Zone Pacific/Apia	 12:33:04 -	LMT	1892 Jul  5
 			-11:26:56 -	LMT	1911
-			-11:30	-	WSST	1950
-			-11:00	WS	S%sT	2011 Dec 29 24:00 # S=Samoa
-			 13:00	WS	WS%sT
+			-11:30	-	-1130	1950
+			-11:00	WS	-11/-10	2011 Dec 29 24:00
+			 13:00	WS	+13/+14
 
 # Solomon Is
 # excludes Bougainville, for which see Papua New Guinea
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Guadalcanal 10:39:48 -	LMT	1912 Oct # Honiara
-			11:00	-	SBT	# Solomon Is Time
+			11:00	-	+11
 
-# Tokelau Is
+# Tokelau
 #
 # From Gwillim Law (2011-12-29)
 # A correspondent informed me that Tokelau, like Samoa, will be skipping
@@ -687,14 +689,14 @@
 # From Paul Eggert (2012-07-25)
 # A Google Books snippet of Appendix to the Journals of the House of
 # Representatives of New Zealand, Session 1948,
-# <http://books.google.com/books?id=ZaVCAQAAIAAJ>, page 65, says Tokelau
+# <https://books.google.com/books?id=ZaVCAQAAIAAJ>, page 65, says Tokelau
 # was "11 hours slow on G.M.T."  Go with Thorsen and assume Shanks & Pottenger
 # are off by an hour starting in 1901.
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Fakaofo	-11:24:56 -	LMT	1901
-			-11:00	-	TKT	2011 Dec 30 # Tokelau Time
-			13:00	-	TKT
+			-11:00	-	-11	2011 Dec 30
+			13:00	-	+13
 
 # Tonga
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
@@ -702,8 +704,8 @@
 Rule	Tonga	2000	only	-	Mar	19	2:00s	0	-
 Rule	Tonga	2000	2001	-	Nov	Sun>=1	2:00	1:00	S
 Rule	Tonga	2001	2002	-	Jan	lastSun	2:00	0	-
-Rule	Tonga	2016	max	-	Nov	Sun>=1	2:00	1:00	S
-Rule	Tonga	2017	max	-	Jan	Sun>=15	3:00	0	-
+Rule	Tonga	2016	only	-	Nov	Sun>=1	2:00	1:00	S
+Rule	Tonga	2017	only	-	Jan	Sun>=15	3:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Tongatapu	12:19:20 -	LMT	1901
 			12:20	-	+1220	1941
@@ -713,7 +715,7 @@
 # Tuvalu
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Funafuti	11:56:52 -	LMT	1901
-			12:00	-	TVT	# Tuvalu Time
+			12:00	-	+12
 
 
 # US minor outlying islands
@@ -737,10 +739,11 @@
 
 # Johnston
 #
-# From Paul Eggert (2014-03-11):
+# From Paul Eggert (2017-02-10):
 # Sometimes Johnston kept Hawaii time, and sometimes it was an hour behind.
 # Details are uncertain.  We have no data for Johnston after 1970, so
-# treat it like Hawaii for now.
+# treat it like Hawaii for now.  Since Johnston is now uninhabited,
+# its link to Pacific/Honolulu is in the 'backward' file.
 #
 # In his memoirs of June 6th to October 4, 1945
 # <http://www.315bw.org/Herb_Bach.htm> (2005), Herbert C. Bach writes,
@@ -756,12 +759,10 @@
 # Operation Fishbowl shot (Tightrope, 1962-11-04).... [See] Herman Hoerlin,
 # "The United States High-Altitude Test Experience: A Review Emphasizing the
 # Impact on the Environment", Los Alamos LA-6405, Oct 1976.
-# http://www.fas.org/sgp/othergov/doe/lanl/docs1/00322994.pdf
+# https://www.fas.org/sgp/othergov/doe/lanl/docs1/00322994.pdf
 # See the table on page 4 where he lists GMT and local times for the tests; a
 # footnote for the JI tests reads that local time is "JI time = Hawaii Time
 # Minus One Hour".
-#
-# See 'northamerica' for Pacific/Johnston.
 
 # Kingman
 # uninhabited
@@ -775,7 +776,7 @@
 # Wake
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Wake	11:06:28 -	LMT	1901
-			12:00	-	WAKT	# Wake Time
+			12:00	-	+12
 
 
 # Vanuatu
@@ -788,12 +789,12 @@
 Rule	Vanuatu	1992	only	-	Oct	Sun>=23	0:00	1:00	S
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Efate	11:13:16 -	LMT	1912 Jan 13 # Vila
-			11:00	Vanuatu	VU%sT	# Vanuatu Time
+			11:00	Vanuatu	+11/+12
 
 # Wallis and Futuna
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Pacific/Wallis	12:15:20 -	LMT	1901
-			12:00	-	WFT	# Wallis & Futuna Time
+			12:00	-	+12
 
 ###############################################################################
 
@@ -804,7 +805,7 @@
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
-# From Paul Eggert (2014-10-31):
+# From Paul Eggert (2017-02-10):
 #
 # Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
@@ -811,8 +812,8 @@
 # San Diego: ACS Publications, Inc. (2003).
 # Unfortunately this book contains many errors and cites no sources.
 #
-# Gwillim Law writes that a good source
-# for recent time zone data is the International Air Transport
+# Many years ago Gwillim Law wrote that a good source
+# for time zone data was the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
 # of the IATA's data after 1990.  Except where otherwise noted,
@@ -824,33 +825,24 @@
 #
 # For data circa 1899, a common source is:
 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
-# http://www.jstor.org/stable/1774359
+# https://www.jstor.org/stable/1774359
 #
 # A reliable and entertaining source about time zones is
 # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
 #
-# I invented the abbreviations marked '*' in the following table;
-# the rest are from earlier versions of this file, or from other sources.
+# The following abbreviations are from other sources.
 # Corrections are welcome!
 #		std	dst
 #		LMT		Local Mean Time
 #	  8:00	AWST	AWDT	Western Australia
-#	  8:45	ACWST	ACWDT	Central Western Australia*
-#	  9:00	JST		Japan
 #	  9:30	ACST	ACDT	Central Australia
 #	 10:00	AEST	AEDT	Eastern Australia
+#	 10:00	GST		Guam through 2000
 #	 10:00	ChST		Chamorro
-#	 10:30	LHST	LHDT	Lord Howe*
-#	 11:00	BST		Bougainville*
 #	 11:30	NZMT	NZST	New Zealand through 1945
 #	 12:00	NZST	NZDT	New Zealand 1946-present
-#	 12:15	CHAST		Chatham through 1945*
-#	 12:45	CHAST	CHADT	Chatham 1946-present*
-#	 13:00	WSST	WSDT	(western) Samoa 2011-present*
-#	-11:30	WSST		Western Samoa through 1950*
 #	-11:00	SST		Samoa
 #	-10:00	HST		Hawaii
-#	- 8:00	PST		Pitcairn*
 #
 # See the 'northamerica' file for Hawaii.
 # See the 'southamerica' file for Easter I and the Galápagos Is.
@@ -980,7 +972,7 @@
 #   AEST ACST AWST AEDT ACDT
 #
 #   Parliamentary Library (2008-11-10)
-#   http://www.aph.gov.au/binaries/library/pubs/rp/2008-09/09rp14.pdf
+#   https://www.aph.gov.au/binaries/library/pubs/rp/2008-09/09rp14.pdf
 #   EST CST WST preferred for standard time; AEST AEDT ACST ACDT also used
 #
 #   The Transport Safety Bureau has an extensive series of accident reports,
@@ -1016,13 +1008,13 @@
 #
 # NSW (including LHI and Broken Hill):
 # Standard Time Act 1987 (updated 1995-04-04)
-# http://www.austlii.edu.au/au/legis/nsw/consol_act/sta1987137/index.html
+# https://www.austlii.edu.au/au/legis/nsw/consol_act/sta1987137/index.html
 # ACT
 # Standard Time and Summer Time Act 1972
-# http://www.austlii.edu.au/au/legis/act/consol_act/stasta1972279/index.html
+# https://www.austlii.edu.au/au/legis/act/consol_act/stasta1972279/index.html
 # SA
 # Standard Time Act, 1898
-# http://www.austlii.edu.au/au/legis/sa/consol_act/sta1898137/index.html
+# https://www.austlii.edu.au/au/legis/sa/consol_act/sta1898137/index.html
 
 # From David Grosz (2005-06-13):
 # It was announced last week that Daylight Saving would be extended by
@@ -1317,7 +1309,7 @@
 # http://abc.net.au/news/regionals/neweng/monthly/regeng-22jul1999-1.htm
 # (1999-07-22).  For now, we'll wait to see if this really happens.
 #
-# Victoria will following NSW.  See:
+# Victoria will follow NSW.  See:
 # Vic to extend daylight saving (1999-07-28)
 # http://abc.net.au/local/news/olympics/1999/07/item19990728112314_1.htm
 #
@@ -1420,7 +1412,7 @@
 # the ACT for all 52 weeks of the year...
 #
 # We have a wrap-up here:
-# http://www.timeanddate.com/news/time/south-australia-extends-dst.html
+# https://www.timeanddate.com/news/time/south-australia-extends-dst.html
 ###############################################################################
 
 # New Zealand
@@ -1474,7 +1466,7 @@
 # From Paul Eggert (2014-07-14):
 # Chatham Island time was formally standardized on 1957-01-01 by
 # New Zealand's Standard Time Amendment Act 1956 (1956-10-26).
-# http://www.austlii.edu.au/nz/legis/hist_act/staa19561956n100244.pdf
+# https://www.austlii.edu.au/nz/legis/hist_act/staa19561956n100244.pdf
 # According to Google Books snippet view, a speaker in the New Zealand
 # parliamentary debates in 1956 said "Clause 78 makes provision for standard
 # time in the Chatham Islands.  The time there is 45 minutes in advance of New
@@ -1589,7 +1581,7 @@
 # the Norfolk Island Museum and the Australian Bureau of Meteorology's
 # Norfolk Island station, and found no record of Norfolk observing DST
 # other than in 1974/5.  See:
-# http://www.timeanddate.com/time/australia/norfolk-island.html
+# https://www.timeanddate.com/time/australia/norfolk-island.html
 
 # Pitcairn
 
@@ -1617,11 +1609,13 @@
 
 # (Western) Samoa and American Samoa
 
-# Howse writes (p 153, citing p 10 of the 1883-11-18 New York Herald)
-# that in 1879 the King of Samoa decided to change
+# Howse writes (p 153) that after the 1879 standardization on Antipodean
+# time by the British governor of Fiji, the King of Samoa decided to change
 # "the date in his kingdom from the Antipodean to the American system,
 # ordaining - by a masterpiece of diplomatic flattery - that
 # the Fourth of July should be celebrated twice in that year."
+# This happened in 1892, according to the Evening News (Sydney) of 1892-07-20.
+# https://www.staff.science.uu.nl/~gent0113/idl/idl.htm
 
 # Although Shanks & Pottenger says they both switched to UT -11:30
 # in 1911, and to -11 in 1950. many earlier sources give -11
@@ -1632,6 +1626,7 @@
 # day in 2011.  Assume also that the Samoas follow the US and New
 # Zealand's "ST"/"DT" style of daylight-saving abbreviations.
 
+
 # Tonga
 
 # From Paul Eggert (1996-01-22):
@@ -1726,6 +1721,15 @@
 # Assume Tonga will observe DST from the first Sunday in November at 02:00
 # through the third Sunday in January at 03:00, like Fiji, for now.
 
+# From David Wade (2017-10-18):
+# In August government was disolved by the King.  The current prime minister
+# continued in office in care taker mode.  It is easy to see that few
+# decisions will be made until elections 16th November.
+#
+# From Paul Eggert (2017-10-18):
+# For now, guess that DST is discontinued.  That's what the IATA is guessing.
+
+
 # Wake
 
 # From Vernice Anderson, Personal Secretary to Philip Jessup,
@@ -1738,7 +1742,7 @@
 # making calculation of time in Washington difficult if not almost
 # impossible.
 #
-# http://www.trumanlibrary.org/wake/meeting.htm
+# https://www.trumanlibrary.org/oralhist/andrsonv.htm
 
 # From Paul Eggert (2003-03-23):
 # We have no other report of DST in Wake Island, so omit this info for now.
@@ -1766,7 +1770,7 @@
 # an international standard, there are some places on the high seas where the
 # correct date is ambiguous.
 
-# From Wikipedia <http://en.wikipedia.org/wiki/Time_zone> (2005-08-31):
+# From Wikipedia <https://en.wikipedia.org/wiki/Time_zone> (2005-08-31):
 # Before 1920, all ships kept local apparent time on the high seas by setting
 # their clocks at night or at the morning sight so that, given the ship's
 # speed and direction, it would be 12 o'clock when the Sun crossed the ship's
--- contrib/tzdata/backward.orig
+++ contrib/tzdata/backward
@@ -61,7 +61,9 @@
 Link	America/Manaus		Brazil/West
 Link	America/Halifax		Canada/Atlantic
 Link	America/Winnipeg	Canada/Central
-Link	America/Regina		Canada/East-Saskatchewan
+# This line is commented out, as the name exceeded the 14-character limit
+# and was an unused misnomer.
+#Link	America/Regina		Canada/East-Saskatchewan
 Link	America/Toronto		Canada/Eastern
 Link	America/Edmonton	Canada/Mountain
 Link	America/St_Johns	Canada/Newfoundland
@@ -96,6 +98,7 @@
 Link	Pacific/Chatham		NZ-CHAT
 Link	America/Denver		Navajo
 Link	Asia/Shanghai		PRC
+Link	Pacific/Honolulu	Pacific/Johnston
 Link	Pacific/Pohnpei		Pacific/Ponape
 Link	Pacific/Pago_Pago	Pacific/Samoa
 Link	Pacific/Chuuk		Pacific/Truk
--- contrib/tzdata/backzone.orig
+++ contrib/tzdata/backzone
@@ -65,7 +65,7 @@
 # Mali (southern)
 Zone	Africa/Bamako	-0:32:00 -	LMT	1912
 			 0:00	-	GMT	1934 Feb 26
-			-1:00	-	WAT	1960 Jun 20
+			-1:00	-	-01	1960 Jun 20
 			 0:00	-	GMT
 
 # Central African Republic
@@ -75,7 +75,7 @@
 # Gambia
 Zone	Africa/Banjul	-1:06:36 -	LMT	1912
 			-1:06:36 -	BMT	1935 # Banjul Mean Time
-			-1:00	-	WAT	1964
+			-1:00	-	-01	1964
 			 0:00	-	GMT
 
 # Malawi
@@ -93,18 +93,18 @@
 # Guinea
 Zone	Africa/Conakry	-0:54:52 -	LMT	1912
 			 0:00	-	GMT	1934 Feb 26
-			-1:00	-	WAT	1960
+			-1:00	-	-01	1960
 			 0:00	-	GMT
 
 # Senegal
 Zone	Africa/Dakar	-1:09:44 -	LMT	1912
-			-1:00	-	WAT	1941 Jun
+			-1:00	-	-01	1941 Jun
 			 0:00	-	GMT
 
 # Tanzania
 Zone Africa/Dar_es_Salaam 2:37:08 -	LMT	1931
 			3:00	-	EAT	1948
-			2:45	-	BEAUT	1961
+			2:45	-	+0245	1961
 			3:00	-	EAT
 
 # Djibouti
@@ -122,14 +122,14 @@
 # The International Hydrographic Bulletin, 1932-33, p 63 says that
 # Sierra Leone would advance its clocks by 20 minutes on 1933-10-01.
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	SL	1935	1942	-	Jun	 1	0:00	0:40	SLST
-Rule	SL	1935	1942	-	Oct	 1	0:00	0	WAT
-Rule	SL	1957	1962	-	Jun	 1	0:00	1:00	SLST
+Rule	SL	1935	1942	-	Jun	 1	0:00	0:40	-0020
+Rule	SL	1935	1942	-	Oct	 1	0:00	0	-01
+Rule	SL	1957	1962	-	Jun	 1	0:00	1:00	+01
 Rule	SL	1957	1962	-	Sep	 1	0:00	0	GMT
 Zone	Africa/Freetown	-0:53:00 -	LMT	1882
 			-0:53:00 -	FMT	1913 Jun # Freetown Mean Time
 			-1:00	SL	%s	1957
-			 0:00	SL	%s
+			 0:00	SL	GMT/+01
 
 # Botswana
 # From Paul Eggert (2013-02-21):
@@ -153,8 +153,8 @@
 # Uganda
 Zone	Africa/Kampala	2:09:40 -	LMT	1928 Jul
 			3:00	-	EAT	1930
-			2:30	-	BEAT	1948
-			2:45	-	BEAUT	1957
+			2:30	-	+0230	1948
+			2:45	-	+0245	1957
 			3:00	-	EAT
 
 # Rwanda
@@ -177,11 +177,11 @@
 #
 # Shanks gives 1911-05-26 for the transition to WAT,
 # evidently confusing the date of the Portuguese decree
-# http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
+# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
 # with the date that it took effect, namely 1912-01-01.
 #
 Zone	Africa/Luanda	0:52:56	-	LMT	1892
-			0:52:04	-	AOT	1912 Jan  1 # Angola Time
+			0:52:04	-	LMT	1912 Jan  1 # Luanda Mean Time?
 			1:00	-	WAT
 
 # Democratic Republic of the Congo (east)
@@ -216,12 +216,12 @@
 # Somalia
 Zone Africa/Mogadishu	3:01:28 -	LMT	1893 Nov
 			3:00	-	EAT	1931
-			2:30	-	BEAT	1957
+			2:30	-	+0230	1957
 			3:00	-	EAT
 
 # Niger
 Zone	Africa/Niamey	 0:08:28 -	LMT	1912
-			-1:00	-	WAT	1934 Feb 26
+			-1:00	-	-01	1934 Feb 26
 			 0:00	-	GMT	1960
 			 1:00	-	WAT
 
@@ -228,7 +228,7 @@
 # Mauritania
 Zone Africa/Nouakchott	-1:03:48 -	LMT	1912
 			 0:00	-	GMT	1934 Feb 26
-			-1:00	-	WAT	1960 Nov 28
+			-1:00	-	-01	1960 Nov 28
 			 0:00	-	GMT
 
 # Burkina Faso
@@ -264,19 +264,19 @@
 # The name "Comodoro Rivadavia" exceeds the 14-byte POSIX limit.
 Zone America/Argentina/ComodRivadavia -4:30:00 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  3
-			-4:00	-	WART	1991 Oct 20
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 Jun  1
-			-4:00	-	WART	2004 Jun 20
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  3
+			-4:00	-	-04	1991 Oct 20
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 Jun  1
+			-4:00	-	-04	2004 Jun 20
+			-3:00	-	-03
 
 # Aruba
 Zone	America/Aruba	-4:40:24 -	LMT	1912 Feb 12 # Oranjestad
-			-4:30	-	ANT	1965 # Netherlands Antilles Time
+			-4:30	-	-0430	1965
 			-4:00	-	AST
 
 # Cayman Is
@@ -365,12 +365,12 @@
 # Formosa (FM), La Pampa (LP), Chubut (CH)
 Zone America/Rosario	-4:02:40 -	LMT	1894 Nov
 			-4:16:44 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Jul
-			-3:00	-	ART	1999 Oct  3  0:00
-			-4:00	Arg	AR%sT	2000 Mar  3  0:00
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Jul
+			-3:00	-	-03	1999 Oct  3  0:00
+			-4:00	Arg	-04/-03	2000 Mar  3  0:00
+			-3:00	-	-03
 
 # St Kitts-Nevis
 Zone America/St_Kitts	-4:10:52 -	LMT	1912 Mar  2 # Basseterre
@@ -403,12 +403,12 @@
 # Milne says 2:59:54 was the meridian of the saluting battery at Aden,
 # and that Yemen was at 1:55:56, the meridian of the Hagia Sophia.
 Zone	Asia/Aden	2:59:54	-	LMT	1950
-			3:00	-	AST
+			3:00	-	+03
 
 # Bahrain
 Zone	Asia/Bahrain	3:22:20 -	LMT	1920     # Manamah
-			4:00	-	GST	1972 Jun
-			3:00	-	AST
+			4:00	-	+04	1972 Jun
+			3:00	-	+03
 
 # India
 #
@@ -431,7 +431,7 @@
 # counties Deqing, Enping, Kaiping, Luoding, Taishan, Xinxing,
 # Yangchun, Yangjiang, Yu'nan, and Yunfu.
 Zone	Asia/Chongqing	7:06:20	-	LMT	1928     # or Chungking
-			7:00	-	LONT	1980 May # Long-shu Time
+			7:00	-	+07	1980 May
 			8:00	PRC	C%sT
 Link Asia/Chongqing Asia/Chungking
 
@@ -442,43 +442,43 @@
 # October 1954, with exact date and time unspecified.
 Zone	Asia/Hanoi	7:03:24 -	LMT	1906 Jul  1
 			7:06:30	-	PLMT	1911 May  1
-			7:00	-	ICT	1942 Dec 31 23:00
-			8:00	-	IDT	1945 Mar 14 23:00
-			9:00	-	JST	1945 Sep  2
-			7:00	-	ICT	1947 Apr  1
-			8:00	-	IDT	1954 Oct
-			7:00	-	ICT
+			7:00	-	+07	1942 Dec 31 23:00
+			8:00	-	+08	1945 Mar 14 23:00
+			9:00	-	+09	1945 Sep  2
+			7:00	-	+07	1947 Apr  1
+			8:00	-	+08	1954 Oct
+			7:00	-	+07
 
 # China
 # Changbai Time ("Long-white Time", Long-white = Heilongjiang area)
 # Heilongjiang (except Mohe county), Jilin
 Zone	Asia/Harbin	8:26:44	-	LMT	1928     # or Haerbin
-			8:30	-	CHAT	1932 Mar # Changbai Time
+			8:30	-	+0830	1932 Mar
 			8:00	-	CST	1940
-			9:00	-	CHAT	1966 May
-			8:30	-	CHAT	1980 May
+			9:00	-	+09	1966 May
+			8:30	-	+0830	1980 May
 			8:00	PRC	C%sT
 
 # far west China
 Zone	Asia/Kashgar	5:03:56	-	LMT	1928     # or Kashi or Kaxgar
-			5:30	-	KAST	1940     # Kashgar Time
-			5:00	-	KAST	1980 May
+			5:30	-	+0530	1940
+			5:00	-	+05	1980 May
 			8:00	PRC	C%sT
 
 # Kuwait
 Zone	Asia/Kuwait	3:11:56 -	LMT	1950
-			3:00	-	AST
+			3:00	-	+03
 
 
 # Oman
 # Milne says 3:54:24 was the meridian of the Muscat Tidal Observatory.
 Zone	Asia/Muscat	3:54:24 -	LMT	1920
-			4:00	-	GST
+			4:00	-	+04
 
 # India
 # From Paul Eggert (2014-08-11), after a heads-up from Stephen Colebourne:
 # According to a Portuguese decree (1911-05-26)
-# http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
+# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
 # Portuguese India switched to UT +05 on 1912-01-01.
 #Zone	Asia/Panaji	[not enough info to complete]
 
@@ -491,12 +491,12 @@
 # transitions there.
 Zone	Asia/Phnom_Penh	6:59:40 -	LMT	1906 Jul  1
 			7:06:30	-	PLMT	1911 May  1
-			7:00	-	ICT	1942 Dec 31 23:00
-			8:00	-	IDT	1945 Mar 14 23:00
-			9:00	-	JST	1945 Sep  2
-			7:00	-	ICT	1947 Apr  1
-			8:00	-	IDT	1953 Nov  9
-			7:00	-	ICT
+			7:00	-	+07	1942 Dec 31 23:00
+			8:00	-	+08	1945 Mar 14 23:00
+			9:00	-	+09	1945 Sep  2
+			7:00	-	+07	1947 Apr  1
+			8:00	-	+08	1953 Nov  9
+			7:00	-	+07
 
 # Israel
 Zone	Asia/Tel_Aviv	2:19:04 -	LMT	1880
@@ -511,16 +511,16 @@
 # this is probably wrong but it's better than guessing no transition.
 Zone	Asia/Vientiane	6:50:24 -	LMT	1906 Jul  1
 			7:06:30	-	PLMT	1911 May  1
-			7:00	-	ICT	1942 Dec 31 23:00
-			8:00	-	IDT	1945 Mar 14 23:00
-			9:00	-	JST	1945 Sep  2
-			7:00	-	ICT	1947 Apr  1
-			8:00	-	IDT	1955 Apr 15
-			7:00	-	ICT
+			7:00	-	+07	1942 Dec 31 23:00
+			8:00	-	+08	1945 Mar 14 23:00
+			9:00	-	+09	1945 Sep  2
+			7:00	-	+07	1947 Apr  1
+			8:00	-	+08	1955 Apr 15
+			7:00	-	+07
 
 # Jan Mayen
 # From Whitman:
-Zone Atlantic/Jan_Mayen	-1:00	-	EGT
+Zone Atlantic/Jan_Mayen	-1:00	-	-01
 
 # St Helena
 Zone Atlantic/St_Helena	-0:22:48 -	LMT	1890 # Jamestown
@@ -540,10 +540,10 @@
 
 # Guernsey
 # Data from Joseph S. Myers
-# http://mm.icann.org/pipermail/tz/2013-September/019883.html
+# https://mm.icann.org/pipermail/tz/2013-September/019883.html
 # References to be added
-# LMT Location - 49.27N -2.33E - St.Peter Port
-Zone	Europe/Guernsey	-0:09:19 -	LMT	1913 Jun 18
+# LMT is for Town Church, St. Peter Port, 49 degrees 27'17"N 2 degrees 32'10"W
+Zone	Europe/Guernsey	-0:10:09 -	LMT	1913 Jun 18
 			 0:00	GB-Eire	%s	1940 Jul  2
 			 1:00	C-Eur	CE%sT	1945 May  8
 			 0:00	GB-Eire	%s	1968 Oct 27
@@ -555,11 +555,11 @@
 #
 # From Lester Caine (2013-09-04):
 # The Isle of Man legislation is now on-line at
-# <http://www.legislation.gov.im>, starting with the original Statutory
+# <https://www.legislation.gov.im>, starting with the original Statutory
 # Time Act in 1883 and including additional confirmation of some of
 # the dates of the 'Summer Time' orders originating at
 # Westminster.  There is a little uncertainty as to the starting date
-# of the first summer time in 1916 which may have be announced a
+# of the first summer time in 1916 which may have been announced a
 # couple of days late.  There is still a substantial number of
 # documents to work through, but it is thought that every GB change
 # was also implemented on the island.
@@ -574,10 +574,10 @@
 
 # Jersey
 # Data from Joseph S. Myers
-# http://mm.icann.org/pipermail/tz/2013-September/019883.html
+# https://mm.icann.org/pipermail/tz/2013-September/019883.html
 # References to be added
-# LMT Location - 49.187N -2.107E - St. Helier
-Zone	Europe/Jersey	-0:08:25 -	LMT	1898 Jun 11 16:00u
+# LMT is for Parish Church, St. Helier, 49 degrees 11'0.57"N 2 degrees 6'24.33"W
+Zone	Europe/Jersey	-0:08:26 -	LMT	1898 Jun 11 16:00u
 			 0:00	GB-Eire	%s	1940 Jul  2
 			 1:00	C-Eur	CE%sT	1945 May  8
 			 0:00	GB-Eire	%s	1968 Oct 27
@@ -663,15 +663,13 @@
 #  "   3:00P Ar. MIDWAY ISLAND . . . . . . . . . M.L.T. Lv. 6:00A  "
 #
 Zone Pacific/Midway	-11:49:28 -	LMT	1901
-			-11:00	-	NST	1956 Jun  3
-			-11:00	1:00	NDT	1956 Sep  2
-			-11:00	-	NST	1967 Apr    # N=Nome
-			-11:00	-	BST	1983 Nov 30 # B=Bering
-			-11:00	-	SST	            # S=Samoa
+			-11:00	-	-11	1956 Jun  3
+			-11:00	1:00	-10	1956 Sep  2
+			-11:00	-	-11
 
 # N Mariana Is
 Zone Pacific/Saipan	-14:17:00 -	LMT	1844 Dec 31
 			 9:43:00 -	LMT	1901
-			 9:00	-	MPT	1969 Oct    # N Mariana Is Time
-			10:00	-	MPT	2000 Dec 23
+			 9:00	-	+09	1969 Oct
+			10:00	-	+10	2000 Dec 23
 			10:00	-	ChST	# Chamorro Standard Time
--- contrib/tzdata/calendars.orig
+++ contrib/tzdata/calendars
@@ -0,0 +1,173 @@
+----- Calendrical issues -----
+
+As mentioned in Theory.html, although calendrical issues are out of
+scope for tzdb, they indicate the sort of problems that we would run
+into if we extended tzdb further into the past.  The following
+information and sources go beyond Theory.html's brief discussion.
+They sometimes disagree.
+
+
+France
+
+Gregorian calendar adopted 1582-12-20.
+French Revolutionary calendar used 1793-11-24 through 1805-12-31,
+and (in Paris only) 1871-05-06 through 1871-05-23.
+
+
+Russia
+
+From Chris Carrier (1996-12-02):
+On 1929-10-01 the Soviet Union instituted an "Eternal Calendar"
+with 30-day months plus 5 holidays, with a 5-day week.
+On 1931-12-01 it changed to a 6-day week; in 1934 it reverted to the
+Gregorian calendar while retaining the 6-day week; on 1940-06-27 it
+reverted to the 7-day week.  With the 6-day week the usual days
+off were the 6th, 12th, 18th, 24th and 30th of the month.
+(Source: Evitiar Zerubavel, _The Seven Day Circle_)
+
+
+Mark Brader reported a similar story in "The Book of Calendars", edited
+by Frank Parise (1982, Facts on File, ISBN 0-8719-6467-8), page 377.  But:
+
+From: Petteri Sulonen (via Usenet)
+Date: 14 Jan 1999 00:00:00 GMT
+...
+
+If your source is correct, how come documents between 1929 and 1940 were
+still dated using the conventional, Gregorian calendar?
+
+I can post a scan of a document dated December 1, 1934, signed by
+Yenukidze, the secretary, on behalf of Kalinin, the President of the
+Executive Committee of the Supreme Soviet, if you like.
+
+
+
+Sweden (and Finland)
+
+From: Mark Brader
+Subject: Re: Gregorian reform - a part of locale?
+<news:1996Jul6.012937.29190@sq.com>
+Date: 1996-07-06
+
+In 1700, Denmark made the transition from Julian to Gregorian.  Sweden
+decided to *start* a transition in 1700 as well, but rather than have one of
+those unsightly calendar gaps :-), they simply decreed that the next leap
+year after 1696 would be in 1744 - putting the whole country on a calendar
+different from both Julian and Gregorian for a period of 40 years.
+
+However, in 1704 something went wrong and the plan was not carried through;
+they did, after all, have a leap year that year.  And one in 1708.  In 1712
+they gave it up and went back to Julian, putting 30 days in February that
+year!...
+
+Then in 1753, Sweden made the transition to Gregorian in the usual manner,
+getting there only 13 years behind the original schedule.
+
+(A previous posting of this story was challenged, and Swedish readers
+produced the following references to support it: "Tideräkning och historia"
+by Natanael Beckman (1924) and "Tid, en bok om tideräkning och
+kalenderväsen" by Lars-Olof Lodén (1968).
+
+
+Grotefend's data
+
+From: "Michael Palmer" [with one obvious typo fixed]
+Subject: Re: Gregorian Calendar (was Re: Another FHC related question
+Newsgroups: soc.genealogy.german
+Date: Tue, 9 Feb 1999 02:32:48 -800
+...
+
+The following is a(n incomplete) listing, arranged chronologically, of
+European states, with the date they converted from the Julian to the
+Gregorian calendar:
+
+04/15 Oct 1582 - Italy (with exceptions), Spain, Portugal, Poland (Roman
+                 Catholics and Danzig only)
+09/20 Dec 1582 - France, Lorraine
+
+21 Dec 1582/
+   01 Jan 1583 - Holland, Brabant, Flanders, Hennegau
+10/21 Feb 1583 - bishopric of Liege (Lüttich)
+13/24 Feb 1583 - bishopric of Augsburg
+04/15 Oct 1583 - electorate of Trier
+05/16 Oct 1583 - Bavaria, bishoprics of Freising, Eichstedt, Regensburg,
+                 Salzburg, Brixen
+13/24 Oct 1583 - Austrian Oberelsaß and Breisgau
+20/31 Oct 1583 - bishopric of Basel
+02/13 Nov 1583 - duchy of Jülich-Berg
+02/13 Nov 1583 - electorate and city of Köln
+04/15 Nov 1583 - bishopric of Würzburg
+11/22 Nov 1583 - electorate of Mainz
+16/27 Nov 1583 - bishopric of Strassburg and the margraviate of Baden
+17/28 Nov 1583 - bishopric of Münster and duchy of Cleve
+14/25 Dec 1583 - Steiermark
+
+06/17 Jan 1584 - Austria and Bohemia
+11/22 Jan 1584 - Lucerne, Uri, Schwyz, Zug, Freiburg, Solothurn
+12/23 Jan 1584 - Silesia and the Lausitz
+22 Jan/
+   02 Feb 1584 - Hungary (legally on 21 Oct 1587)
+      Jun 1584 - Unterwalden
+01/12 Jul 1584 - duchy of Westfalen
+
+16/27 Jun 1585 - bishopric of Paderborn
+
+14/25 Dec 1590 - Transylvania
+
+22 Aug/
+   02 Sep 1612 - duchy of Prussia
+
+13/24 Dec 1614 - Pfalz-Neuburg
+
+          1617 - duchy of Kurland (reverted to the Julian calendar in
+                 1796)
+
+          1624 - bishopric of Osnabrück
+
+          1630 - bishopric of Minden
+
+15/26 Mar 1631 - bishopric of Hildesheim
+
+          1655 - Kanton Wallis
+
+05/16 Feb 1682 - city of Strassburg
+
+18 Feb/
+   01 Mar 1700 - Protestant Germany (including Swedish possessions in
+                 Germany), Denmark, Norway
+30 Jun/
+   12 Jul 1700 - Gelderland, Zutphen
+10 Nov/
+   12 Dec 1700 - Utrecht, Overijssel
+
+31 Dec 1700/
+   12 Jan 1701 - Friesland, Groningen, Zürich, Bern, Basel, Geneva,
+                 Turgau, and Schaffhausen
+
+          1724 - Glarus, Appenzell, and the city of St. Gallen
+
+01 Jan 1750    - Pisa and Florence
+
+02/14 Sep 1752 - Great Britain
+
+17 Feb/
+   01 Mar 1753 - Sweden
+
+1760-1812      - Graubünden
+
+The Russian empire (including Finland and the Baltic states) did not
+convert to the Gregorian calendar until the Soviet revolution of 1917.
+
+Source: H. Grotefend, _Taschenbuch der Zeitrechnung des deutschen
+Mittelalters und der Neuzeit_, herausgegeben von Dr. O. Grotefend
+(Hannover: Hahnsche Buchhandlung, 1941), pp. 26-28.
+
+-----
+
+This file is in the public domain, so clarified as of 2009-05-17 by
+Arthur David Olson.
+
+-----
+Local Variables:
+coding: utf-8
+End:
--- contrib/tzdata/checklinks.awk.orig
+++ contrib/tzdata/checklinks.awk
@@ -9,7 +9,7 @@
     Zone = "\n"
 }
 
-/^Zone/ {
+/^Z/ {
     if (defined[$2]) {
 	if (defined[$2] == Zone) {
 	    printf "%s: Zone has duplicate definition\n", $2
@@ -21,7 +21,7 @@
     defined[$2] = Zone
 }
 
-/^Link/ {
+/^L/ {
     if (defined[$3]) {
 	if (defined[$3] == Zone) {
 	    printf "%s: Link with same name as Zone\n", $3
--- contrib/tzdata/europe.orig
+++ contrib/tzdata/europe
@@ -6,7 +6,7 @@
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
-# From Paul Eggert (2014-10-31):
+# From Paul Eggert (2017-02-10):
 #
 # Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
@@ -13,8 +13,8 @@
 # San Diego: ACS Publications, Inc. (2003).
 # Unfortunately this book contains many errors and cites no sources.
 #
-# Gwillim Law writes that a good source
-# for recent time zone data is the International Air Transport
+# Many years ago Gwillim Law wrote that a good source
+# for time zone data was the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
 # of the IATA's data after 1990.  Except where otherwise noted,
@@ -37,7 +37,7 @@
 #	[PDF] (1914-03)
 #
 #	Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
-#	<http://www.jstor.org/stable/1774359>.  He writes:
+#	<https://www.jstor.org/stable/1774359>.  He writes:
 #	"It is requested that corrections and additions to these tables
 #	may be sent to Mr. John Milne, Royal Geographical Society,
 #	Savile Row, London."  Nowadays please email them to tz@iana.org.
@@ -44,7 +44,7 @@
 #
 #	Byalokoz EL. New Counting of Time in Russia since July 1, 1919.
 #	This Russian-language source was consulted by Vladimir Karpinsky; see
-#	http://mm.icann.org/pipermail/tz/2014-August/021320.html
+#	https://mm.icann.org/pipermail/tz/2014-August/021320.html
 #	The full Russian citation is:
 #	Бялокоз, Евгений Людвигович. Новый счет времени в течении суток
 #	введенный декретом Совета народных комиссаров для всей России с 1-го
@@ -56,26 +56,23 @@
 #	History of Summer Time
 #	<http://pcdsh01.on.br/HISTHV.htm>
 #	(1998-09-21, in Portuguese)
-
 #
 # I invented the abbreviations marked '*' in the following table;
-# the rest are from earlier versions of this file, or from other sources.
-# Corrections are welcome!
-#                   std dst  2dst
-#                   LMT           Local Mean Time
-#       -4:00       AST ADT       Atlantic
-#       -3:00       WGT WGST      Western Greenland*
-#       -1:00       EGT EGST      Eastern Greenland*
-#        0:00       GMT BST  BDST Greenwich, British Summer
-#        0:00       GMT IST       Greenwich, Irish Summer
-#        0:00       WET WEST WEMT Western Europe
-#        0:19:32.13 AMT NST       Amsterdam, Netherlands Summer (1835-1937)*
-#        0:20       NET NEST      Netherlands (1937-1940)*
-#        1:00       BST           British Standard (1968-1971)
-#        1:00       CET CEST CEMT Central Europe
-#        1:00:14    SET           Swedish (1879-1899)*
-#        2:00       EET EEST      Eastern Europe
-#        3:00       MSK MSD       Moscow
+# the rest are variants of the "xMT" pattern for a city's mean time,
+# or are from other sources.  Corrections are welcome!
+#                   std  dst  2dst
+#                   LMT             Local Mean Time
+#       -4:00       AST  ADT        Atlantic
+#        0:00       GMT  BST  BDST  Greenwich, British Summer
+#        0:00       GMT  IST        Greenwich, Irish Summer
+#        0:00       WET  WEST WEMT  Western Europe
+#        0:19:32.13 AMT* NST*       Amsterdam, Netherlands Summer (1835-1937)
+#        1:00       BST             British Standard (1968-1971)
+#        1:00       CET  CEST CEMT  Central Europe
+#        1:00:14    SET             Swedish (1879-1899)
+#        1:36:34    RMT* LST*       Riga, Latvian Summer (1880-1926)*
+#        2:00       EET  EEST       Eastern Europe
+#        3:00       MSK  MSD  MDST* Moscow
 
 # From Peter Ilieve (1994-12-04),
 # The original six [EU members]: Belgium, France, (West) Germany, Italy,
@@ -190,7 +187,7 @@
 # foundations of civilization throughout the world.
 #	-- "A Silent Toast to William Willett", Pictorial Weekly;
 #	republished in Finest Hour (Spring 2002) 1(114):26
-#	http://www.winstonchurchill.org/images/finesthour/Vol.01%20No.114.pdf
+#	https://www.winstonchurchill.org/publications/finest-hour/finest-hour-114/a-silent-toast-to-william-willett-by-winston-s-churchill
 
 # From Paul Eggert (2015-08-08):
 # The OED Supplement says that the English originally said "Daylight Saving"
@@ -228,8 +225,8 @@
 # official designation; the reply of the 21st was that there wasn't
 # but he couldn't think of anything better than the "Double British
 # Summer Time" that the BBC had been using informally.
-# http://www.polyomino.org.uk/british-time/bbc-19410418.png
-# http://www.polyomino.org.uk/british-time/ho-19410421.png
+# https://www.polyomino.org.uk/british-time/bbc-19410418.png
+# https://www.polyomino.org.uk/british-time/ho-19410421.png
 
 # From Sir Alexander Maxwell in the above-mentioned letter (1941-04-21):
 # [N]o official designation has as far as I know been adopted for the time
@@ -246,13 +243,13 @@
 # the history of summer time legislation in the United Kingdom.
 # Since 1998 Joseph S. Myers has been updating
 # and extending this list, which can be found in
-# http://www.polyomino.org.uk/british-time/
+# https://www.polyomino.org.uk/british-time/
 
 # From Joseph S. Myers (1998-01-06):
 #
 # The legal time in the UK outside of summer time is definitely GMT, not UTC;
 # see Lord Tanlaw's speech
-# http://www.publications.parliament.uk/pa/ld199798/ldhansrd/vo970611/text/70611-10.htm#70611-10_head0
+# https://www.publications.parliament.uk/pa/ld199798/ldhansrd/vo970611/text/70611-10.htm#70611-10_head0
 # (Lords Hansard 11 June 1997 columns 964 to 976).
 
 # From Paul Eggert (2006-03-22):
@@ -298,7 +295,7 @@
 # Irish 'public feeling (was) outraged by forcing of English time on us'."
 # -- Parsons M. Dublin lost its time zone - and 25 minutes - after 1916 Rising.
 # Irish Times 2014-10-27.
-# http://www.irishtimes.com/news/politics/dublin-lost-its-time-zone-and-25-minutes-after-1916-rising-1.1977411
+# https://www.irishtimes.com/news/politics/dublin-lost-its-time-zone-and-25-minutes-after-1916-rising-1.1977411
 
 # From Joseph S. Myers (2005-01-26):
 # Irish laws are available online at <http://www.irishstatutebook.ie>.
@@ -351,6 +348,12 @@
 # Justice (tel +353 1 678 9711) who confirmed to me that the correct name is
 # "Irish Summer Time", abbreviated to "IST".
 
+# Michael Deckers (2017-06-01) gave the following URLs for Ireland's
+# Summer Time Act, 1925 and Summer Time Orders, 1926 and 1947:
+# http://www.irishstatutebook.ie/eli/1925/act/8/enacted/en/print.html
+# http://www.irishstatutebook.ie/eli/1926/sro/919/made/en/print.html
+# http://www.irishstatutebook.ie/eli/1947/sro/71/made/en/print.html
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 # Summer Time Act, 1916
 Rule	GB-Eire	1916	only	-	May	21	2:00s	1:00	BST
@@ -475,14 +478,14 @@
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Europe/Dublin	-0:25:00 -	LMT	1880 Aug  2
-			-0:25:21 -	DMT	1916 May 21  2:00
+			-0:25:21 -	DMT	1916 May 21  2:00s # Dublin MT
 			-0:25:21 1:00	IST	1916 Oct  1  2:00s
 			 0:00	GB-Eire	%s	1921 Dec  6 # independence
-			 0:00	GB-Eire	GMT/IST	1940 Feb 25  2:00
-			 0:00	1:00	IST	1946 Oct  6  2:00
-			 0:00	-	GMT	1947 Mar 16  2:00
-			 0:00	1:00	IST	1947 Nov  2  2:00
-			 0:00	-	GMT	1948 Apr 18  2:00
+			 0:00	GB-Eire	GMT/IST	1940 Feb 25  2:00s
+			 0:00	1:00	IST	1946 Oct  6  2:00s
+			 0:00	-	GMT	1947 Mar 16  2:00s
+			 0:00	1:00	IST	1947 Nov  2  2:00s
+			 0:00	-	GMT	1948 Apr 18  2:00s
 			 0:00	GB-Eire	GMT/IST	1968 Oct 27
 			 1:00	-	IST	1971 Oct 31  2:00u
 			 0:00	GB-Eire	GMT/IST	1996
@@ -628,7 +631,7 @@
 # Council of Ministers of the USSR from 1989-03-14 No. 227.
 #
 # I did not find full texts of these acts.  For the 1989 one we have
-# title at http://base.garant.ru/70754136/ :
+# title at https://base.garant.ru/70754136/ :
 # "About change in calculation of time on the territories of
 # Lithuanian SSR, Latvian SSR and Estonian SSR, Astrakhan,
 # Kaliningrad, Kirov, Kuybyshev, Ulyanovsk and Uralsk oblasts".
@@ -659,7 +662,7 @@
 # http://bmockbe.ru/events/?ID=7583
 #
 # Medvedev signed a law on the calculation of the time (in russian):
-# http://www.regnum.ru/news/polit/1413906.html
+# https://www.regnum.ru/news/polit/1413906.html
 
 # From Arthur David Olson (2011-06-15):
 # Take "abolishing daylight saving time" to mean that time is now considered
@@ -786,7 +789,7 @@
 # Sources (Russian language):
 # http://www.belta.by/ru/all_news/society/V-Belarusi-otmenjaetsja-perexod-na-sezonnoe-vremja_i_572952.html
 # http://naviny.by/rubrics/society/2011/09/16/ic_articles_116_175144/
-# http://news.tut.by/society/250578.html
+# https://news.tut.by/society/250578.html
 #
 # From Alexander Bokovoy (2014-10-09):
 # Belarussian government decided against changing to winter time....
@@ -901,7 +904,7 @@
 # Cyprus
 # Please see the 'asia' file for Asia/Nicosia.
 
-# Czech Republic
+# Czech Republic / Czechia
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Czech	1945	only	-	Apr	 8	2:00s	1:00	S
 Rule	Czech	1945	only	-	Nov	18	2:00s	0	-
@@ -1064,16 +1067,16 @@
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Danmarkshavn -1:14:40 -	LMT	1916 Jul 28
-			-3:00	-	WGT	1980 Apr  6  2:00
-			-3:00	EU	WG%sT	1996
+			-3:00	-	-03	1980 Apr  6  2:00
+			-3:00	EU	-03/-02	1996
 			0:00	-	GMT
 Zone America/Scoresbysund -1:27:52 -	LMT	1916 Jul 28 # Ittoqqortoormiit
-			-2:00	-	CGT	1980 Apr  6  2:00
-			-2:00	C-Eur	CG%sT	1981 Mar 29
-			-1:00	EU	EG%sT
+			-2:00	-	-02	1980 Apr  6  2:00
+			-2:00	C-Eur	-02/-01	1981 Mar 29
+			-1:00	EU	-01/+00
 Zone America/Godthab	-3:26:56 -	LMT	1916 Jul 28 # Nuuk
-			-3:00	-	WGT	1980 Apr  6  2:00
-			-3:00	EU	WG%sT
+			-3:00	-	-03	1980 Apr  6  2:00
+			-3:00	EU	-03/-02
 Zone America/Thule	-4:35:08 -	LMT	1916 Jul 28 # Pituffik air base
 			-4:00	Thule	A%sT
 
@@ -1107,7 +1110,7 @@
 # for their standard and summer times. He says no, they use "suveaeg"
 # (summer time) and "talveaeg" (winter time).
 
-# From The Baltic Times <http://www.baltictimes.com/> (1999-09-09)
+# From The Baltic Times <https://www.baltictimes.com/> (1999-09-09)
 # via Steffen Thorsen:
 # This year will mark the last time Estonia shifts to summer time,
 # a council of the ruling coalition announced Sept. 6....
@@ -1159,7 +1162,7 @@
 # This is documented in Heikki Oja: Aikakirja 2007, published by The Almanac
 # Office of University of Helsinki, ISBN 952-10-3221-9, available online (in
 # Finnish) at
-# http://almanakka.helsinki.fi/aikakirja/Aikakirja2007kokonaan.pdf
+# https://almanakka.helsinki.fi/aikakirja/Aikakirja2007kokonaan.pdf
 #
 # Page 105 (56 in PDF version) has a handy table of all past daylight savings
 # transitions. It is easy enough to interpret without Finnish skills.
@@ -1172,7 +1175,7 @@
 
 # From Konstantin Hyppönen (2014-06-13):
 # [Heikki Oja's book Aikakirja 2013]
-# http://almanakka.helsinki.fi/images/aikakirja/Aikakirja2013kokonaan.pdf
+# https://almanakka.helsinki.fi/images/aikakirja/Aikakirja2013kokonaan.pdf
 # pages 104-105, including a scan from a newspaper published on Apr 2 1942
 # say that ... [o]n Apr 2 1942, 24 o'clock (which means Apr 3 1942,
 # 00:00), clocks were moved one hour forward. The newspaper
@@ -1302,7 +1305,7 @@
 
 # From Jörg Schilling (2002-10-23):
 # In 1945, Berlin was switched to Moscow Summer time (GMT+4) by
-# http://www.dhm.de/lemo/html/biografien/BersarinNikolai/
+# https://www.dhm.de/lemo/html/biografien/BersarinNikolai/
 # General [Nikolai] Bersarin.
 
 # From Paul Eggert (2003-03-08):
@@ -1488,7 +1491,7 @@
 Rule	Iceland	1967	only	-	Oct	29	 1:00s	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Atlantic/Reykjavik	-1:28	-	LMT	1908
-			-1:00	Iceland	IS%sT	1968 Apr  7  1:00s
+			-1:00	Iceland	-01/+00	1968 Apr  7  1:00s
 			 0:00	-	GMT
 
 # Italy
@@ -1527,7 +1530,7 @@
 # From Paul Eggert (2016-10-27):
 # Go with INRiM for DST rules, except as corrected by Inglis for 1944
 # for the Kingdom of Italy.  This is consistent with Renzo Baldini.
-# Model Rome's occupation by using using C-Eur rules from 1943-09-10
+# Model Rome's occupation by using C-Eur rules from 1943-09-10
 # to 1944-06-04; although Rome was an open city during this period, it
 # was effectively controlled by Germany.
 #
@@ -1842,7 +1845,7 @@
 # Following Moldova and neighboring Ukraine- Transnistria (Pridnestrovie)-
 # Tiraspol will go back to winter time on October 30, 2011.
 # News from Moldova (in russian):
-# http://ru.publika.md/link_317061.html
+# https://ru.publika.md/link_317061.html
 
 # From Roman Tudos (2015-07-02):
 # http://lex.justice.md/index.php?action=view&view=doc&lang=1&id=355077
@@ -1849,7 +1852,7 @@
 # From Paul Eggert (2015-07-01):
 # The abovementioned official link to IGO1445-868/2014 states that
 # 2014-10-26's fallback transition occurred at 03:00 local time.  Also,
-# http://www.trm.md/en/social/la-30-martie-vom-trece-la-ora-de-vara
+# https://www.trm.md/en/social/la-30-martie-vom-trece-la-ora-de-vara
 # says the 2014-03-30 spring-forward transition was at 02:00 local time.
 # Guess that since 1997 Moldova has switched one hour before the EU.
 
@@ -1921,7 +1924,7 @@
 # Amsterdam mean time.
 
 # The data entries before 1945 are taken from
-# http://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm
+# https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Neth	1916	only	-	May	 1	0:00	1:00	NST	# Netherlands Summer Time
@@ -1952,7 +1955,7 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Europe/Amsterdam	0:19:32 -	LMT	1835
 			0:19:32	Neth	%s	1937 Jul  1
-			0:20	Neth	NE%sT	1940 May 16  0:00 # Dutch Time
+			0:20	Neth +0020/+0120 1940 May 16  0:00
 			1:00	C-Eur	CE%sT	1945 Apr  2  2:00
 			1:00	Neth	CE%sT	1977
 			1:00	EU	CE%sT
@@ -2002,7 +2005,7 @@
 # so it must have diverged from Oslo time during the war, as Oslo was
 # keeping Berlin time.
 #
-# <http://home.no.net/janmayen/history.htm> says that the meteorologists
+# <https://www.jan-mayen.no/history.htm> says that the meteorologists
 # burned down their station in 1940 and left the island, but returned in
 # 1941 with a small Norwegian garrison and continued operations despite
 # frequent air attacks from Germans.  In 1943 the Americans established a
@@ -2040,7 +2043,7 @@
 Rule	Poland	1945	only	-	Nov	 1	0:00	0	-
 # For 1946 on the source is Kazimierz Borkowski,
 # Toruń Center for Astronomy, Dept. of Radio Astronomy, Nicolaus Copernicus U.,
-# http://www.astro.uni.torun.pl/~kb/Artykuly/U-PA/Czas2.htm#tth_tAb1
+# https://www.astro.uni.torun.pl/~kb/Artykuly/U-PA/Czas2.htm#tth_tAb1
 # Thanks to Przemysław Augustyniak (2005-05-28) for this reference.
 # He also gives these further references:
 # Mon Pol nr 13, poz 162 (1995) <http://www.abc.com.pl/serwis/mp/1995/0162.htm>
@@ -2074,7 +2077,7 @@
 #
 # From Paul Eggert (2014-08-11), after a heads-up from Stephen Colebourne:
 # According to a Portuguese decree (1911-05-26)
-# http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
+# https://dre.pt/application/dir/pdf1sdip/1911/05/12500/23132313.pdf
 # Lisbon was at -0:36:44.68, but switched to GMT on 1912-01-01 at 00:00.
 # Round the old offset to -0:36:45.  This agrees with Willett but disagrees
 # with Shanks, who says the transition occurred on 1911-05-24 at 00:00 for
@@ -2169,16 +2172,34 @@
 			 0:00	W-Eur	WE%sT	1992 Sep 27  1:00s
 			 1:00	EU	CE%sT	1996 Mar 31  1:00u
 			 0:00	EU	WE%sT
+# This Zone can be simplified once we assume zic %z.
 Zone Atlantic/Azores	-1:42:40 -	LMT	1884        # Ponta Delgada
 			-1:54:32 -	HMT	1912 Jan  1 # Horta Mean Time
-			-2:00	Port	AZO%sT	1966 Apr  3  2:00  # Azores Time
-			-1:00	Port	AZO%sT	1983 Sep 25  1:00s
-			-1:00	W-Eur	AZO%sT	1992 Sep 27  1:00s
+			-2:00	Port	-02/-01	1942 Apr 25 22:00s
+			-2:00	Port	+00	1942 Aug 15 22:00s
+			-2:00	Port	-02/-01	1943 Apr 17 22:00s
+			-2:00	Port	+00	1943 Aug 28 22:00s
+			-2:00	Port	-02/-01	1944 Apr 22 22:00s
+			-2:00	Port	+00	1944 Aug 26 22:00s
+			-2:00	Port	-02/-01	1945 Apr 21 22:00s
+			-2:00	Port	+00	1945 Aug 25 22:00s
+			-2:00	Port	-02/-01	1966 Apr  3  2:00
+			-1:00	Port	-01/+00	1983 Sep 25  1:00s
+			-1:00	W-Eur	-01/+00	1992 Sep 27  1:00s
 			 0:00	EU	WE%sT	1993 Mar 28  1:00u
-			-1:00	EU	AZO%sT
+			-1:00	EU	-01/+00
+# This Zone can be simplified once we assume zic %z.
 Zone Atlantic/Madeira	-1:07:36 -	LMT	1884        # Funchal
 			-1:07:36 -	FMT	1912 Jan  1 # Funchal Mean Time
-			-1:00	Port	MAD%sT	1966 Apr  3  2:00 # Madeira Time
+			-1:00	Port	-01/+00	1942 Apr 25 22:00s
+			-1:00	Port	+01	1942 Aug 15 22:00s
+			-1:00	Port	-01/+00	1943 Apr 17 22:00s
+			-1:00	Port	+01	1943 Aug 28 22:00s
+			-1:00	Port	-01/+00	1944 Apr 22 22:00s
+			-1:00	Port	+01	1944 Aug 26 22:00s
+			-1:00	Port	-01/+00	1945 Apr 21 22:00s
+			-1:00	Port	+01	1945 Aug 25 22:00s
+			-1:00	Port	-01/+00	1966 Apr  3  2:00
 			 0:00	Port	WE%sT	1983 Sep 25  1:00s
 			 0:00	EU	WE%sT
 
@@ -2238,7 +2259,7 @@
 # 2011 No. 725" and contains no other dates or "effective date" information.
 #
 # Another source is
-# http://www.rg.ru/2011/09/06/chas-zona-dok.html
+# https://rg.ru/2011/09/06/chas-zona-dok.html
 # which, according to translate.google.com, begins "Resolution of the
 # Government of the Russian Federation on August 31, 2011 N 725" and also
 # contains "Date first official publication: September 6, 2011 Posted on:
@@ -2246,7 +2267,7 @@
 # does not contain any "effective date" information.
 #
 # Another source is
-# http://en.wikipedia.org/wiki/Oymyakonsky_District#cite_note-RuTime-7
+# https://en.wikipedia.org/wiki/Oymyakonsky_District#cite_note-RuTime-7
 # which, in note 8, contains "Resolution No. 725 of August 31, 2011...
 # Effective as of after 7 days following the day of the official publication"
 # but which does not contain any reference to September 6, 2011.
@@ -2282,7 +2303,7 @@
 # http://itar-tass.com/obschestvo/1333711
 # http://www.pravo.gov.ru:8080/page.aspx?111660
 # http://www.kremlin.ru/acts/46279
-# From October 26, 2014 the new Russian time zone map will looks like this:
+# From October 26, 2014 the new Russian time zone map will look like this:
 # http://www.worldtimezone.com/dst_news/dst_news_russia-map-2014-07.html
 
 # From Paul Eggert (2006-03-22):
@@ -2329,7 +2350,7 @@
 # with maintenance only and represent our best guesses as to which regions
 # are covered by each zone.  They are not meant to be taken as an authoritative
 # listing.  The region codes listed come from
-# http://en.wikipedia.org/w/?title=Federal_subjects_of_Russia&oldid=611810498
+# https://en.wikipedia.org/w/?title=Federal_subjects_of_Russia&oldid=611810498
 # and are used for convenience only; no guarantees are made regarding their
 # future stability.  ISO 3166-2:RU codes are also listed for first-level
 # divisions where available.
@@ -2494,7 +2515,7 @@
 # http://www.kaliningradka.ru/site_pc/cherez/index.php?ELEMENT_ID=40091
 # says that Kaliningrad decided not to be an exception 2 days before the
 # 1991-03-31 switch and one person at
-# http://izhevsk.ru/forum_light_message/50/682597-m8369040.html
+# https://izhevsk.ru/forum_light_message/50/682597-m8369040.html
 # says he remembers that Samara opted out of the 1992-01-19 exception
 # 2 days before the switch.
 #
@@ -2536,10 +2557,8 @@
 			 3:00	-	MSK
 
 
-# From Tim Parenti (2014-07-03):
-# Europe/Simferopol covers...
-# **	****	Crimea, Republic of
-# **	****	Sevastopol
+# From Paul Eggert (2016-12-06):
+# Europe/Simferopol covers Crimea.
 
 Zone Europe/Simferopol	 2:16:24 -	LMT	1880
 			 2:16	-	SMT	1924 May  2 # Simferopol Mean T
@@ -2568,7 +2587,7 @@
 			 3:00	-	MSK	1997 Mar lastSun  1:00u
 # From Alexander Krivenyshev (2014-03-17):
 # time change at 2:00 (2am) on March 30, 2014
-# http://vz.ru/news/2014/3/17/677464.html
+# https://vz.ru/news/2014/3/17/677464.html
 # From Paul Eggert (2014-03-30):
 # Simferopol and Sevastopol reportedly changed their central town clocks
 # late the previous day, but this appears to have been ceremonial
@@ -2601,10 +2620,9 @@
 			 3:00	-	+03	2016 Mar 27  2:00s
 			 4:00	-	+04
 
-# From Paul Eggert (2016-03-18):
+# From Paul Eggert (2016-11-11):
 # Europe/Volgograd covers:
 # 34	RU-VGG	Volgograd Oblast
-# 64	RU-SAR	Saratov Oblast
 # The 1988 transition is from USSR act No. 5 (1988-01-04).
 
 Zone Europe/Volgograd	 2:57:40 -	LMT	1920 Jan  3
@@ -2617,6 +2635,27 @@
 			 4:00	-	+04	2014 Oct 26  2:00s
 			 3:00	-	+03
 
+# From Paul Eggert (2016-11-11):
+# Europe/Saratov covers:
+# 64	RU-SAR	Saratov Oblast
+
+# From Yuri Konotopov (2016-11-11):
+# Dec 4, 2016 02:00 UTC+3....  Saratov Region's local time will be ... UTC+4.
+# From Stepan Golosunov (2016-11-11):
+# ... Byalokoz listed Saratov on 03:04:18.
+# From Stepan Golosunov (2016-11-22):
+# http://publication.pravo.gov.ru/Document/View/0001201611220031
+
+Zone Europe/Saratov	 3:04:18 -	LMT	1919 Jul  1  0:00u
+			 3:00	-	+03	1930 Jun 21
+			 4:00	Russia	+04/+05	1988 Mar 27  2:00s
+			 3:00	Russia	+03/+04	1991 Mar 31  2:00s
+			 4:00	-	+04	1992 Mar 29  2:00s
+			 3:00	Russia	+03/+04	2011 Mar 27  2:00s
+			 4:00	-	+04	2014 Oct 26  2:00s
+			 3:00	-	+03	2016 Dec  4  2:00s
+			 4:00	-	+04
+
 # From Paul Eggert (2016-03-18):
 # Europe/Kirov covers:
 # 43	RU-KIR	Kirov Oblast
@@ -2731,7 +2770,7 @@
 # suggests that Altai Republic transitioned to Moscow+3 on
 # 1995-05-28.
 #
-# http://regnum.ru/news/society/1957270.html
+# https://regnum.ru/news/society/1957270.html
 # has some historical data for Altai Krai:
 # before 1957: west part on UTC+6, east on UTC+7
 # after 1957: UTC+7
@@ -3105,8 +3144,8 @@
 # districts, but have very similar populations.  In fact, Wikipedia currently
 # lists them both as having 3528 people, exactly 1668 males and 1860 females
 # each!  (Yikes!)
-# http://en.wikipedia.org/w/?title=Srednekolymsky_District&oldid=603435276
-# http://en.wikipedia.org/w/?title=Verkhnekolymsky_District&oldid=594378493
+# https://en.wikipedia.org/w/?title=Srednekolymsky_District&oldid=603435276
+# https://en.wikipedia.org/w/?title=Verkhnekolymsky_District&oldid=594378493
 # Assume this is a mistake, albeit an amusing one.
 #
 # Looking at censuses, the populations of the two municipalities seem to have
@@ -3212,46 +3251,77 @@
 # See Europe/Belgrade.
 
 # Spain
+#
+# From Paul Eggert (2016-12-14):
+#
+# The source for Europe/Madrid before 2013 is:
+# Planesas P. La hora oficial en España y sus cambios.
+# Anuario del Observatorio Astronómico de Madrid (2013, in Spanish).
+# http://astronomia.ign.es/rknowsys-theme/images/webAstro/paginas/documentos/Anuario/lahoraoficialenespana.pdf
+# As this source says that historical time in the Canaries is obscure,
+# and it does not discuss Ceuta, stick with Shanks for now for that data.
+#
+# In the 1918 and 1919 fallback transitions in Spain, the clock for
+# the hour-longer day officially kept going after midnight, so that
+# the repeated instances of that day's 00:00 hour were 24 hours apart,
+# with a fallback transition from the second occurrence of 00:59... to
+# the next day's 00:00.  Our data format cannot represent this
+# directly, and instead repeats the first hour of the next day, with a
+# fallback transition from the next day's 00:59... to 00:00.
+
+# From Michael Deckers (2016-12-15):
+# The Royal Decree of 1900-06-26 quoted by Planesas, online at
+# https://www.boe.es/datos/pdfs/BOE//1900/209/A00383-00384.pdf
+# says in its article 5 (my translation):
+# These dispositions will enter into force beginning with the
+# instant at which, according to the time indicated in article 1,
+# the 1st day of January of 1901 will begin.
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-# For 1917-1919 Whitman gives Apr Sat>=1 - Oct Sat>=1;
-# go with Shanks & Pottenger.
-Rule	Spain	1917	only	-	May	 5	23:00s	1:00	S
-Rule	Spain	1917	1919	-	Oct	 6	23:00s	0	-
-Rule	Spain	1918	only	-	Apr	15	23:00s	1:00	S
-Rule	Spain	1919	only	-	Apr	 5	23:00s	1:00	S
-# Whitman gives 1921 Feb 28 - Oct 14; go with Shanks & Pottenger.
-Rule	Spain	1924	only	-	Apr	16	23:00s	1:00	S
-# Whitman gives 1924 Oct 14; go with Shanks & Pottenger.
-Rule	Spain	1924	only	-	Oct	 4	23:00s	0	-
-Rule	Spain	1926	only	-	Apr	17	23:00s	1:00	S
-# Whitman says no DST in 1929; go with Shanks & Pottenger.
-Rule	Spain	1926	1929	-	Oct	Sat>=1	23:00s	0	-
-Rule	Spain	1927	only	-	Apr	 9	23:00s	1:00	S
-Rule	Spain	1928	only	-	Apr	14	23:00s	1:00	S
-Rule	Spain	1929	only	-	Apr	20	23:00s	1:00	S
-# Whitman gives 1937 Jun 16, 1938 Apr 16, 1940 Apr 13;
-# go with Shanks & Pottenger.
-Rule	Spain	1937	only	-	May	22	23:00s	1:00	S
-Rule	Spain	1937	1939	-	Oct	Sat>=1	23:00s	0	-
-Rule	Spain	1938	only	-	Mar	22	23:00s	1:00	S
-Rule	Spain	1939	only	-	Apr	15	23:00s	1:00	S
-Rule	Spain	1940	only	-	Mar	16	23:00s	1:00	S
-# Whitman says no DST 1942-1945; go with Shanks & Pottenger.
-Rule	Spain	1942	only	-	May	 2	22:00s	2:00	M # Midsummer
-Rule	Spain	1942	only	-	Sep	 1	22:00s	1:00	S
-Rule	Spain	1943	1946	-	Apr	Sat>=13	22:00s	2:00	M
-Rule	Spain	1943	only	-	Oct	 3	22:00s	1:00	S
-Rule	Spain	1944	only	-	Oct	10	22:00s	1:00	S
-Rule	Spain	1945	only	-	Sep	30	 1:00	1:00	S
-Rule	Spain	1946	only	-	Sep	30	 0:00	0	-
+Rule	Spain	1918	only	-	Apr	15	23:00	1:00	S
+Rule	Spain	1918	1919	-	Oct	 6	24:00s	0	-
+Rule	Spain	1919	only	-	Apr	 6	23:00	1:00	S
+Rule	Spain	1924	only	-	Apr	16	23:00	1:00	S
+Rule	Spain	1924	only	-	Oct	 4	24:00s	0	-
+Rule	Spain	1926	only	-	Apr	17	23:00	1:00	S
+Rule	Spain	1926	1929	-	Oct	Sat>=1	24:00s	0	-
+Rule	Spain	1927	only	-	Apr	 9	23:00	1:00	S
+Rule	Spain	1928	only	-	Apr	15	 0:00	1:00	S
+Rule	Spain	1929	only	-	Apr	20	23:00	1:00	S
+# Republican Spain during the civil war; it controlled Madrid until 1939-03-28.
+Rule	Spain	1937	only	-	Jun	16	23:00	1:00	S
+Rule	Spain	1937	only	-	Oct	 2	24:00s	0	-
+Rule	Spain	1938	only	-	Apr	 2	23:00	1:00	S
+Rule	Spain	1938	only	-	Apr	30	23:00	2:00	M
+Rule	Spain	1938	only	-	Oct	 2	24:00	1:00	S
+# The following rules are for unified Spain again.
+#
+# Planesas does not say what happened in Madrid between its fall on
+# 1939-03-28 and the Nationalist spring-forward transition on
+# 1939-04-15.  For lack of better info, assume Madrid's clocks did not
+# change during that period.
+#
+# The first rule is commented out, as it is redundant for Republican Spain.
+#Rule	Spain	1939	only	-	Apr	15	23:00	1:00	S
+Rule	Spain	1939	only	-	Oct	 7	24:00s	0	-
+Rule	Spain	1942	only	-	May	 2	23:00	1:00	S
+Rule	Spain	1942	only	-	Sep	 1	 1:00	0	-
+Rule	Spain	1943	1946	-	Apr	Sat>=13	23:00	1:00	S
+Rule	Spain	1943	1944	-	Oct	Sun>=1	 1:00	0	-
+Rule	Spain	1945	1946	-	Sep	lastSun	 1:00	0	-
 Rule	Spain	1949	only	-	Apr	30	23:00	1:00	S
-Rule	Spain	1949	only	-	Sep	30	 1:00	0	-
-Rule	Spain	1974	1975	-	Apr	Sat>=13	23:00	1:00	S
+Rule	Spain	1949	only	-	Oct	 2	 1:00	0	-
+Rule	Spain	1974	1975	-	Apr	Sat>=12	23:00	1:00	S
 Rule	Spain	1974	1975	-	Oct	Sun>=1	 1:00	0	-
 Rule	Spain	1976	only	-	Mar	27	23:00	1:00	S
 Rule	Spain	1976	1977	-	Sep	lastSun	 1:00	0	-
-Rule	Spain	1977	1978	-	Apr	 2	23:00	1:00	S
-Rule	Spain	1978	only	-	Oct	 1	 1:00	0	-
+Rule	Spain	1977	only	-	Apr	 2	23:00	1:00	S
+Rule	Spain	1978	only	-	Apr	 2	 2:00s	1:00	S
+Rule	Spain	1978	only	-	Oct	 1	 2:00s	0	-
+# Nationalist Spain during the civil war
+#Rule NatSpain	1937	only	-	May	22	23:00	1:00	S
+#Rule NatSpain	1937	1938	-	Oct	Sat>=1	24:00s	0	-
+#Rule NatSpain	1938	only	-	Mar	26	23:00	1:00	S
 # The following rules are copied from Morocco from 1967 through 1978.
 Rule SpainAfrica 1967	only	-	Jun	 3	12:00	1:00	S
 Rule SpainAfrica 1967	only	-	Oct	 1	 0:00	0	-
@@ -3263,11 +3333,11 @@
 Rule SpainAfrica 1978	only	-	Jun	 1	 0:00	1:00	S
 Rule SpainAfrica 1978	only	-	Aug	 4	 0:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone	Europe/Madrid	-0:14:44 -	LMT	1901 Jan  1  0:00s
-			 0:00	Spain	WE%sT	1946 Sep 30
+Zone	Europe/Madrid	-0:14:44 -	LMT	1900 Dec 31 23:45:16
+			 0:00	Spain	WE%sT	1940 Mar 16 23:00
 			 1:00	Spain	CE%sT	1979
 			 1:00	EU	CE%sT
-Zone	Africa/Ceuta	-0:21:16 -	LMT	1901
+Zone	Africa/Ceuta	-0:21:16 -	LMT	1900 Dec 31 23:38:44
 			 0:00	-	WET	1918 May  6 23:00
 			 0:00	1:00	WEST	1918 Oct  7 23:00
 			 0:00	-	WET	1924
@@ -3276,7 +3346,7 @@
 			 1:00	-	CET	1986
 			 1:00	EU	CE%sT
 Zone	Atlantic/Canary	-1:01:36 -	LMT	1922 Mar # Las Palmas de Gran C.
-			-1:00	-	CANT	1946 Sep 30  1:00 # Canaries T
+			-1:00	-	-01	1946 Sep 30  1:00
 			 0:00	-	WET	1980 Apr  6  0:00s
 			 0:00	1:00	WEST	1980 Sep 28  1:00u
 			 0:00	EU	WE%sT
@@ -3396,7 +3466,7 @@
 #
 # From Alois Treindl (2013-09-11):
 # The Federal regulations say
-# http://www.admin.ch/opc/de/classified-compilation/20071096/index.html
+# https://www.admin.ch/opc/de/classified-compilation/20071096/index.html
 # ... the meridian for Bern mean time ... is 7 degrees 26' 22.50".
 # Expressed in time, it is 0h29m45.5s.
 
@@ -3473,9 +3543,9 @@
 # According to the articles linked below, Turkey will change into summer
 # time zone (GMT+3) on March 28, 2011 at 3:00 a.m. instead of March 27.
 # This change is due to a nationwide exam on 27th.
-# http://www.worldbulletin.net/?aType=haber&ArticleID=70872
+# https://www.worldbulletin.net/?aType=haber&ArticleID=70872
 # Turkish:
-# http://www.hurriyet.com.tr/ekonomi/17230464.asp?gid=373
+# https://www.hurriyet.com.tr/yaz-saati-uygulamasi-bir-gun-ileri-alindi-17230464
 
 # From Faruk Pasin (2014-02-14):
 # The DST for Turkey has been changed for this year because of the
@@ -3611,7 +3681,7 @@
 # http://www.segodnya.ua/news/14290482.html
 #
 # Deputies cancelled the winter time (in Russian)
-# http://www.pravda.com.ua/rus/news/2011/09/20/6600616/
+# https://www.pravda.com.ua/rus/news/2011/09/20/6600616/
 #
 # From Philip Pizzey (2011-10-18):
 # Today my Ukrainian colleagues have informed me that the
@@ -3689,7 +3759,7 @@
 # spelling, except omit the apostrophe as it is not allowed in
 # portable Posix file names.
 Zone Europe/Zaporozhye	2:20:40 -	LMT	1880
-			2:20	-	CUT	1924 May  2 # Central Ukraine T
+			2:20	-	+0220	1924 May  2
 			2:00	-	EET	1930 Jun 21
 			3:00	-	MSK	1941 Aug 25
 			1:00	C-Eur	CE%sT	1943 Oct 25
--- contrib/tzdata/leap-seconds.list.orig
+++ contrib/tzdata/leap-seconds.list
@@ -199,10 +199,10 @@
 #	current -- the update time stamp, the data and the name of the file
 #	will not change.
 #
-#	Updated through IERS Bulletin C52
-#	File expires on:  28 June 2017
+#	Updated through IERS Bulletin C54
+#	File expires on:  28 June 2018
 #
-#@	3707596800
+#@	3739132800
 #
 2272060800	10	# 1 Jan 1972
 2287785600	11	# 1 Jul 1972
@@ -247,4 +247,4 @@
 #	the hash line is also ignored in the
 #	computation.
 #
-#h	dacf2c42 2c4765d6 3c797af8 2cf630eb 699c8c67
+#h	5101445a 69948b51 9153e2b 2086e3d8 d54561a3
--- contrib/tzdata/leapseconds.orig
+++ contrib/tzdata/leapseconds
@@ -3,19 +3,18 @@
 # This file is in the public domain.
 
 # This file is generated automatically from the data in the public-domain
-# leap-seconds.list file available from most NIST time servers.
-# If the URL <ftp://time.nist.gov/pub/leap-seconds.list> does not work,
-# you should be able to pick up leap-seconds.list from a secondary NIST server.
-# See <http://tf.nist.gov/tf-cgi/servers.cgi> for a list of secondary servers.
+# leap-seconds.list file, which is copied from:
+# ftp://ftp.nist.gov/pub/time/leap-seconds.list
 # For more about leap-seconds.list, please see
 # The NTP Timescale and Leap Seconds
-# http://www.eecis.udel.edu/~mills/leap.html
+# https://www.eecis.udel.edu/~mills/leap.html
 
 # The International Earth Rotation and Reference Systems Service
 # periodically uses leap seconds to keep UTC to within 0.9 s of UT1
 # (which measures the true angular orientation of the earth in space); see
-# Terry J Quinn, The BIPM and the accurate measure of time,
-# Proc IEEE 79, 7 (July 1991), 894-905 <http://dx.doi.org/10.1109/5.84965>.
+# Levine J. Coordinated Universal Time and the leap second.
+# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995
+# http://ieeexplore.ieee.org/document/7909995/
 # There were no leap seconds before 1972, because the official mechanism
 # accounting for the discrepancy between atomic time and the earth's rotation
 # did not exist until the early 1970s.
@@ -58,5 +57,5 @@
 Leap	2015	Jun	30	23:59:60	+	S
 Leap	2016	Dec	31	23:59:60	+	S
 
-#	Updated through IERS Bulletin C52
-#	File expires on:  28 June 2017
+#	Updated through IERS Bulletin C54
+#	File expires on:  28 June 2018
--- contrib/tzdata/leapseconds.awk.orig
+++ contrib/tzdata/leapseconds.awk
@@ -8,19 +8,18 @@
   print "# This file is in the public domain."
   print ""
   print "# This file is generated automatically from the data in the public-domain"
-  print "# leap-seconds.list file available from most NIST time servers."
-  print "# If the URL <ftp://time.nist.gov/pub/leap-seconds.list> does not work,"
-  print "# you should be able to pick up leap-seconds.list from a secondary NIST server."
-  print "# See <http://tf.nist.gov/tf-cgi/servers.cgi> for a list of secondary servers."
+  print "# leap-seconds.list file, which is copied from:"
+  print "# ftp://ftp.nist.gov/pub/time/leap-seconds.list"
   print "# For more about leap-seconds.list, please see"
   print "# The NTP Timescale and Leap Seconds"
-  print "# http://www.eecis.udel.edu/~mills/leap.html"
+  print "# https://www.eecis.udel.edu/~mills/leap.html"
   print ""
   print "# The International Earth Rotation and Reference Systems Service"
   print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1"
   print "# (which measures the true angular orientation of the earth in space); see"
-  print "# Terry J Quinn, The BIPM and the accurate measure of time,"
-  print "# Proc IEEE 79, 7 (July 1991), 894-905 <http://dx.doi.org/10.1109/5.84965>."
+  print "# Levine J. Coordinated Universal Time and the leap second."
+  print "# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995"
+  print "# http://ieeexplore.ieee.org/document/7909995/"
   print "# There were no leap seconds before 1972, because the official mechanism"
   print "# accounting for the discrepancy between atomic time and the earth's rotation"
   print "# did not exist until the early 1970s."
--- contrib/tzdata/northamerica.orig
+++ contrib/tzdata/northamerica
@@ -105,10 +105,13 @@
 # Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
 # In the introduction, Oboler spoke of "Eastern Peace Time."
 # An AltaVista search turned up:
-# http://rowayton.org/rhs/hstaug45.html
+# https://web.archive.org/web/20000926032210/http://rowayton.org/rhs/hstaug45.html
 # "When the time is announced over the radio now, it is 'Eastern Peace
 # Time' instead of the old familiar 'Eastern War Time.'  Peace is wonderful."
 # (August 1945) by way of confirmation.
+#
+# From Paul Eggert (2017-09-23):
+# This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.
 
 # From Joseph Gallant citing
 # George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
@@ -178,22 +181,6 @@
 Zone	MST7MDT		 -7:00	US	M%sT
 Zone	PST8PDT		 -8:00	US	P%sT
 
-# From Bob Devine (1988-01-28):
-# ...Alaska (and Hawaii) had the timezone names changed in 1967.
-#    old			 new
-#    Pacific Standard Time(PST)  -same-
-#    Yukon Standard Time(YST)    -same-
-#    Central Alaska S.T. (CAT)   Alaska-Hawaii St[an]dard Time (AHST)
-#    Nome Standard Time (NT)     Bering Standard Time (BST)
-#
-# ...Alaska's timezone lines were redrawn in 1983 to give only 2 tz.
-#    The YST zone now covers nearly all of the state, AHST just part
-#    of the Aleutian islands.   No DST.
-
-# From Paul Eggert (1995-12-19):
-# The tables below use 'NST', not 'NT', for Nome Standard Time.
-# I invented 'CAWT' for Central Alaska War Time.
-
 # From U. S. Naval Observatory (1989-01-19):
 # USA  EASTERN       5 H  BEHIND UTC    NEW YORK, WASHINGTON
 # USA  EASTERN       4 H  BEHIND UTC    APR 3 - OCT 30
@@ -250,6 +237,21 @@
 #	Samoa standard time
 # The law doesn't give abbreviations.
 #
+# From Paul Eggert (2016-12-19):
+# Here are URLs for the 1918 and 1966 legislation:
+# http://uscode.house.gov/statviewer.htm?volume=40&page=451
+# http://uscode.house.gov/statviewer.htm?volume=80&page=108
+# Although the 1918 names were officially "United States Standard
+# Eastern Time" and similarly for "Central", "Mountain", "Pacific",
+# and "Alaska", in practice "Standard" was placed just before "Time",
+# as codified in 1966.  In practice, Alaska time was abbreviated "AST"
+# before 1968.  Summarizing the 1967 name changes:
+#	1918 names			1967 names
+#  -08	Standard Pacific Time (PST)	Pacific standard time (PST)
+#  -09	(unofficial) Yukon (YST)	Yukon standard time (YST)
+#  -10	Standard Alaska Time (AST)	Alaska-Hawaii standard time (AHST)
+#  -11	(unofficial) Nome (NST)		Bering standard time (BST)
+#
 # From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
 # Public law 106-564 (2000-12-23) introduced ... "Chamorro Standard Time"
 # for time in Guam and the Northern Marianas.  See the file "australasia".
@@ -258,7 +260,7 @@
 # HST and HDT are standardized abbreviations for Hawaii-Aleutian
 # standard and daylight times.  See section 9.47 (p 234) of the
 # U.S. Government Printing Office Style Manual (2008)
-# http://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf
+# https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf
 
 # From Arthur David Olson, 2005-08-09
 # The following was signed into law on 2005-08-08.
@@ -305,6 +307,15 @@
 # Roberts, city administrator in Phenix City. as saying "We are in the Central
 # time zone, but we do go by the Eastern time zone because so many people work
 # in Columbus."
+#
+# From Paul Eggert (2017-02-22):
+# Four cities are involved.  The two not mentioned above are Smiths Station
+# and Valley.  Barbara Brooks, Valley's assistant treasurer, heard it started
+# because West Point Pepperell textile mills were in Alabama while the
+# corporate office was in Georgia, and residents voted to keep Eastern
+# time even after the mills closed.  See: Kazek K. Did you know which
+# Alabama towns are in a different time zone?  al.com 2017-02-06.
+# http://www.al.com/living/index.ssf/2017/02/do_you_know_which_alabama_town.html
 
 # From Paul Eggert (2014-09-06):
 # Monthly Notices of the Royal Astronomical Society 44, 4 (1884-02-08), 208
@@ -338,7 +349,7 @@
 # western Tennessee, most of Texas, Wisconsin
 
 # From Larry M. Smith (2006-04-26) re Wisconsin:
-# http://www.legis.state.wi.us/statutes/Stat0175.pdf ...
+# https://docs.legis.wisconsin.gov/statutes/statutes/175.pdf
 # is currently enforced at the 01:00 time of change.  Because the local
 # "bar time" in the state corresponds to 02:00, a number of citations
 # are issued for the "sale of class 'B' alcohol after prohibited
@@ -347,7 +358,7 @@
 # From Douglas R. Bomberg (2007-03-12):
 # Wisconsin has enacted (nearly eleventh-hour) legislation to get WI
 # Statue 175 closer in synch with the US Congress' intent....
-# http://www.legis.state.wi.us/2007/data/acts/07Act3.pdf
+# https://docs.legis.wisconsin.gov/2007/related/acts/3
 
 # From an email administrator of the City of Fort Pierre, SD (2015-12-21):
 # Fort Pierre is technically located in the Mountain time zone as is
@@ -394,7 +405,7 @@
 # ...it appears that Mercer County, North Dakota, changed from the
 # mountain time zone to the central time zone at the last transition from
 # daylight-saving to standard time (on Nov. 7, 2010):
-# http://www.gpo.gov/fdsys/pkg/FR-2010-09-29/html/2010-24376.htm
+# https://www.gpo.gov/fdsys/pkg/FR-2010-09-29/html/2010-24376.htm
 # http://www.bismarcktribune.com/news/local/article_1eb1b588-c758-11df-b472-001cc4c03286.html
 
 # From Andy Lipscomb (2011-01-24):
@@ -445,7 +456,7 @@
 # legal time, and is not part of the data here.)  See:
 # Ross SA. An energy crisis from the past: Northern California in 1948.
 # Working Paper No. 8, Institute of Governmental Studies, UC Berkeley,
-# 1973-11.  http://escholarship.org/uc/item/8x22k30c
+# 1973-11.  https://escholarship.org/uc/item/8x22k30c
 #
 # In another measure to save electricity, DST was instituted from 1948-03-14
 # at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move
@@ -466,8 +477,8 @@
 # which established DST from April's last Sunday at 01:00 until September's
 # last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed
 # the fall-back date to October's last Sunday. See:
-# http://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
-# http://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
+# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
+# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
 #
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
 Rule	CA	1948	only	-	Mar	14	2:01	1:00	D
@@ -482,22 +493,33 @@
 			-8:00	US	P%sT
 
 # Alaska
-# AK%sT is the modern abbreviation for -9:00 per USNO.
+# AK%sT is the modern abbreviation for -09 per USNO.
 #
-# From Paul Eggert (2001-05-30):
+# From Paul Eggert (2017-06-15):
 # Howse writes that Alaska switched from the Julian to the Gregorian calendar,
 # and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
-# This was on 1867-10-18, a Friday; the previous day was 1867-10-06 Julian,
-# also a Friday.  Include only the time zone part of this transition,
-# ignoring the switch from Julian to Gregorian, since we can't represent
-# the Julian calendar.
+# On Friday, 1867-10-18 (Gregorian), at precisely 15:30 local time, the
+# Russian forts and fleet at Sitka fired salutes to mark the ceremony of
+# formal transfer.  See the Sacramento Daily Union (1867-11-14), p 3, col 2.
+# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SDU18671114.2.12.1
+# Sitka workers did not change their calendars until Sunday, 1867-10-20,
+# and so celebrated two Sundays that week.  See: Ahllund T (tr Hallamaa P).
+# From the memoirs of a Finnish workman. Alaska History. 2006 Fall;21(2):1-25.
+# http://alaskahistoricalsociety.org/wp-content/uploads/2016/12/Ahllund-2006-Memoirs-of-a-Finnish-Workman.pdf
+# Include only the time zone part of this transition, ignoring the switch
+# from Julian to Gregorian, since we can't represent the Julian calendar.
 #
-# As far as we know, none of the exact locations mentioned below were
+# As far as we know, of the locations mentioned below only Sitka was
 # permanently inhabited in 1867 by anyone using either calendar.
-# (Yakutat was colonized by the Russians in 1799, but the settlement
-# was destroyed in 1805 by a Yakutat-kon war party.)  However, there
-# were nearby inhabitants in some cases and for our purposes perhaps
-# it's best to simply use the official transition.
+# (Yakutat was colonized by the Russians in 1799, but the settlement was
+# destroyed in 1805 by a Yakutat-kon war party.)  Many of Alaska's inhabitants
+# were unaware of the US acquisition of Alaska, much less of any calendar or
+# time change.  However, the Russian-influenced part of Alaska did observe
+# Russian time, and it is more accurate to model this than to ignore it.
+# The database format requires an exact transition time; use the Russian
+# salute as a somewhat-arbitrary time for the formal transfer of control for
+# all of Alaska.  Sitka's UTC offset is -9:01:13; adjust its 15:30 to the
+# local times of other Alaskan locations so that they change simultaneously.
 
 # From Paul Eggert (2014-07-18):
 # One opinion of the early-1980s turmoil in Alaska over time zones and
@@ -550,10 +572,10 @@
 # It seems Metlakatla did go off PST on Sunday, November 1, changing
 # their time to AKST and are going to follow Alaska's DST, switching
 # between AKST and AKDT from now on....
-# http://www.krbd.org/2015/10/30/annette-island-times-they-are-a-changing/
+# https://www.krbd.org/2015/10/30/annette-island-times-they-are-a-changing/
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone America/Juneau	 15:02:19 -	LMT	1867 Oct 18
+Zone America/Juneau	 15:02:19 -	LMT	1867 Oct 19 15:33:32
 			 -8:57:41 -	LMT	1900 Aug 20 12:00
 			 -8:00	-	PST	1942
 			 -8:00	US	P%sT	1946
@@ -563,7 +585,7 @@
 			 -8:00	US	P%sT	1983 Oct 30  2:00
 			 -9:00	US	Y%sT	1983 Nov 30
 			 -9:00	US	AK%sT
-Zone America/Sitka	 14:58:47 -	LMT	1867 Oct 18
+Zone America/Sitka	 14:58:47 -	LMT	1867 Oct 19 15:30
 			 -9:01:13 -	LMT	1900 Aug 20 12:00
 			 -8:00	-	PST	1942
 			 -8:00	US	P%sT	1946
@@ -571,7 +593,7 @@
 			 -8:00	US	P%sT	1983 Oct 30  2:00
 			 -9:00	US	Y%sT	1983 Nov 30
 			 -9:00	US	AK%sT
-Zone America/Metlakatla	 15:13:42 -	LMT	1867 Oct 18
+Zone America/Metlakatla	 15:13:42 -	LMT	1867 Oct 19 15:44:55
 			 -8:46:18 -	LMT	1900 Aug 20 12:00
 			 -8:00	-	PST	1942
 			 -8:00	US	P%sT	1946
@@ -579,7 +601,7 @@
 			 -8:00	US	P%sT	1983 Oct 30  2:00
 			 -8:00	-	PST	2015 Nov  1  2:00
 			 -9:00	US	AK%sT
-Zone America/Yakutat	 14:41:05 -	LMT	1867 Oct 18
+Zone America/Yakutat	 14:41:05 -	LMT	1867 Oct 19 15:12:18
 			 -9:18:55 -	LMT	1900 Aug 20 12:00
 			 -9:00	-	YST	1942
 			 -9:00	US	Y%sT	1946
@@ -586,17 +608,15 @@
 			 -9:00	-	YST	1969
 			 -9:00	US	Y%sT	1983 Nov 30
 			 -9:00	US	AK%sT
-Zone America/Anchorage	 14:00:24 -	LMT	1867 Oct 18
+Zone America/Anchorage	 14:00:24 -	LMT	1867 Oct 19 14:31:37
 			 -9:59:36 -	LMT	1900 Aug 20 12:00
-			-10:00	-	CAT	1942
-			-10:00	US	CAT/CAWT 1945 Aug 14 23:00u
-			-10:00	US	CAT/CAPT 1946 # Peace
-			-10:00	-	CAT	1967 Apr
+			-10:00	-	AST	1942
+			-10:00	US	A%sT	1967 Apr
 			-10:00	-	AHST	1969
 			-10:00	US	AH%sT	1983 Oct 30  2:00
 			 -9:00	US	Y%sT	1983 Nov 30
 			 -9:00	US	AK%sT
-Zone America/Nome	 12:58:21 -	LMT	1867 Oct 18
+Zone America/Nome	 12:58:22 -	LMT	1867 Oct 19 13:29:35
 			-11:01:38 -	LMT	1900 Aug 20 12:00
 			-11:00	-	NST	1942
 			-11:00	US	N%sT	1946
@@ -605,7 +625,7 @@
 			-11:00	US	B%sT	1983 Oct 30  2:00
 			 -9:00	US	Y%sT	1983 Nov 30
 			 -9:00	US	AK%sT
-Zone America/Adak	 12:13:21 -	LMT	1867 Oct 18
+Zone America/Adak	 12:13:22 -	LMT	1867 Oct 19 12:44:35
 			-11:46:38 -	LMT	1900 Aug 20 12:00
 			-11:00	-	NST	1942
 			-11:00	US	N%sT	1946
@@ -641,7 +661,7 @@
 # "Hawaiian Time" by Robert C. Schmitt and Doak C. Cox appears on pages 207-225
 # of volume 26 of The Hawaiian Journal of History (1992). As of 2010-12-09,
 # the article is available at
-# http://evols.library.manoa.hawaii.edu/bitstream/10524/239/2/JL26215.pdf
+# https://evols.library.manoa.hawaii.edu/bitstream/10524/239/2/JL26215.pdf
 # and indicates that standard time was adopted effective noon, January
 # 13, 1896 (page 218), that in "1933, the Legislature decreed daylight
 # saving for the period between the last Sunday of each April and the
@@ -680,7 +700,6 @@
 			-10:30	1:00	HDT	1945 Sep 30  2:00
 			-10:30	-	HST	1947 Jun  8  2:00
 			-10:00	-	HST
-Link Pacific/Honolulu Pacific/Johnston
 
 # Now we turn to US areas that have diverged from the consensus since 1970.
 
@@ -741,7 +760,7 @@
 # Indiana
 #
 # For a map of Indiana's time zone regions, see:
-# http://en.wikipedia.org/wiki/Time_in_Indiana
+# https://en.wikipedia.org/wiki/Time_in_Indiana
 #
 # From Paul Eggert (2007-08-17):
 # Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
@@ -968,7 +987,7 @@
 # From Paul Eggert (2001-07-16):
 # The final rule was published in the
 # Federal Register 65, 160 (2000-08-17), pp 50154-50158.
-# http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2000_register&docid=fr17au00-22
+# https://www.gpo.gov/fdsys/pkg/FR-2000-08-17/html/00-20854.htm
 #
 Zone America/Kentucky/Monticello -5:39:24 - LMT	1883 Nov 18 12:20:36
 			-6:00	US	C%sT	1946
@@ -994,7 +1013,7 @@
 # West Wendover, NV officially switched from Pacific to mountain time on
 # 1999-10-31.  See the
 # Federal Register 64, 203 (1999-10-21), pp 56705-56707.
-# http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=1999_register&docid=fr21oc99-15
+# https://www.gpo.gov/fdsys/pkg/FR-1999-10-21/html/99-27240.htm
 # However, the Federal Register says that West Wendover already operated
 # on mountain time, and the rule merely made this official;
 # hence a separate tz entry is not needed.
@@ -1024,12 +1043,23 @@
 # one hour in 1914."  This change is not in Shanks.  We have no more
 # info, so omit this for now.
 #
+# From Paul Eggert (2017-07-26):
+# Although Shanks says Detroit observed DST in 1967 from 06-14 00:01
+# until 10-29 00:01, I now see multiple reports that this is incorrect.
+# For example, according to a 50-year anniversary report about the 1967
+# Detroit riots and a major-league doubleheader on 1967-07-23, "By the time
+# the last fly ball of the doubleheader settled into the glove of leftfielder
+# Lenny Green, it was after 7 p.m.  Detroit did not observe daylight saving
+# time, so light was already starting to fail.  Twilight was made even deeper
+# by billowing columns of smoke that ascended in an unbroken wall north of the
+# ballpark."  See: Dow B. Detroit '67: As violence unfolded, Tigers played two
+# at home vs. Yankees. Detroit Free Press 2017-07-23.
+# https://www.freep.com/story/sports/mlb/tigers/2017/07/23/detroit-tigers-1967-riot-new-york-yankees/499951001/
+#
 # Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
 Rule	Detroit	1948	only	-	Apr	lastSun	2:00	1:00	D
 Rule	Detroit	1948	only	-	Sep	lastSun	2:00	0	S
-Rule	Detroit	1967	only	-	Jun	14	2:00	1:00	D
-Rule	Detroit	1967	only	-	Oct	lastSun	2:00	0	S
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Detroit	-5:32:11 -	LMT	1905
 			-6:00	-	CST	1915 May 15  2:00
@@ -1068,7 +1098,7 @@
 ################################################################################
 
 
-# From Paul Eggert (2014-10-31):
+# From Paul Eggert (2017-02-10):
 #
 # Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
@@ -1075,8 +1105,8 @@
 # San Diego: ACS Publications, Inc. (2003).
 # Unfortunately this book contains many errors and cites no sources.
 #
-# Gwillim Law writes that a good source
-# for recent time zone data is the International Air Transport
+# Many years ago Gwillim Law wrote that a good source
+# for time zone data was the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
 # of the IATA's data after 1990.  Except where otherwise noted,
@@ -1093,7 +1123,7 @@
 #	[PDF] (1914-03)
 #
 #	Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
-#	<http://www.jstor.org/stable/1774359>.
+#	<https://www.jstor.org/stable/1774359>.
 #
 # See the 'europe' file for Greenland.
 
@@ -1139,19 +1169,19 @@
 # The British Columbia government announced yesterday that it will
 # adjust daylight savings next year to align with changes in the
 # U.S. and the rest of Canada....
-# http://www2.news.gov.bc.ca/news_releases_2005-2009/2006AG0014-000330.htm
+# https://archive.news.gov.bc.ca/releases/news_releases_2005-2009/2006AG0014-000330.htm
 # ...
 # Nova Scotia
 # Daylight saving time will be extended by four weeks starting in 2007....
-# http://www.gov.ns.ca/just/regulations/rg2/2006/ma1206.pdf
+# https://www.novascotia.ca/just/regulations/rg2/2006/ma1206.pdf
 #
 # [For New Brunswick] the new legislation dictates that the time change is to
 # be done at 02:00 instead of 00:01.
-# http://www.gnb.ca/0062/acts/BBA-2006/Chap-19.pdf
+# https://www.gnb.ca/0062/acts/BBA-2006/Chap-19.pdf
 # ...
 # Manitoba has traditionally changed the clock every fall at 03:00.
 # As of 2006, the transition is to take place one hour earlier at 02:00.
-# http://web2.gov.mb.ca/laws/statutes/ccsm/o030e.php
+# https://web2.gov.mb.ca/laws/statutes/ccsm/o030e.php
 # ...
 # [Alberta, Ontario, Quebec] will follow US rules.
 # http://www.qp.gov.ab.ca/documents/spring/CH03_06.CFM
@@ -1165,7 +1195,7 @@
 # http://www.hoa.gov.nl.ca/hoa/bills/Bill0634.htm
 # ...
 # Yukon
-# http://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
+# https://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
 # ...
 # N.W.T. will follow US rules.  Whoever maintains the government web site
 # does not seem to believe in bookmarks.  To see the news release, click the
@@ -1186,8 +1216,8 @@
 # time and daylight saving time arrangements in Canada circa 1998.
 #
 # National Research Council Canada maintains info about time zones and DST.
-# http://www.nrc-cnrc.gc.ca/eng/services/time/time_zones.html
-# http://www.nrc-cnrc.gc.ca/eng/services/time/faq/index.html#Q5
+# https://www.nrc-cnrc.gc.ca/eng/services/time/time_zones.html
+# https://www.nrc-cnrc.gc.ca/eng/services/time/faq/index.html#Q5
 # Its unofficial information is often taken from Matthews and Vincent.
 
 # From Paul Eggert (2006-06-27):
@@ -1224,11 +1254,13 @@
 
 # Newfoundland and Labrador
 
-# From Paul Eggert (2000-10-02):
-# Matthews and Vincent (1998) write that Labrador should use NST/NDT,
-# but the only part of Labrador that follows the rules is the
-# southeast corner, including Port Hope Simpson and Mary's Harbour,
-# but excluding, say, Black Tickle.
+# From Paul Eggert (2017-10-14):
+# Legally Labrador should observe Newfoundland time; see:
+# McLeod J. Labrador time - legal or not? St. John's Telegram, 2017-10-07
+# http://www.thetelegram.com/news/local/labrador-time--legal-or-not-154860/
+# Matthews and Vincent (1998) write that the only part of Labrador
+# that follows the rules is the southeast corner, including Port Hope
+# Simpson and Mary's Harbour, but excluding, say, Black Tickle.
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	StJohns	1917	only	-	Apr	 8	2:00	1:00	D
@@ -1428,7 +1460,7 @@
 # http://www.justice.gouv.qc.ca/english/publications/generale/temps-minganie-a.htm
 # that the coastal strip from just east of Natashquan to Blanc-Sablon
 # observes Atlantic standard time all year round.
-# http://www.assnat.qc.ca/Media/Process.aspx?MediaId=ANQ.Vigie.Bll.DocumentGenerique_8845en
+# https://www.assnat.qc.ca/Media/Process.aspx?MediaId=ANQ.Vigie.Bll.DocumentGenerique_8845en
 # says this common practice was codified into law as of 2007.
 # For lack of better info, guess this practice began around 1970, contra to
 # Shanks & Pottenger who have this region observing AST/ADT.
@@ -1460,6 +1492,11 @@
 # earlier in June).
 #
 # Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
+#
+# From Paul Eggert (2017-07-08):
+# For more on Orillia, see: Daubs K. Bold attempt at daylight saving
+# time became a comic failure in Orillia. Toronto Star 2017-07-08.
+# https://www.thestar.com/news/insight/2017/07/08/bold-attempt-at-daylight-saving-time-became-a-comic-failure-in-orillia.html
 
 # From Paul Eggert (1997-10-17):
 # Mark Brader writes that an article in the 1997-10-14 Toronto Star
@@ -1951,7 +1988,7 @@
 #	* 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
 #	c. 7 defines Yukon standard time as UTC-9....
 #	see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
-#	[http://canlii.ca/t/7vhg]
+#	[https://www.canlii.org/en/ca/laws/stat/rsc-1985-c-i-21/latest/rsc-1985-c-i-21.html]
 #	* C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
 #	* O.I.C. 1980/02 established DST.
 #	* O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
@@ -2016,7 +2053,7 @@
 #     hours behind Greenwich Time.
 #
 # * Yukon Standard Time defined as Pacific Standard Time, YCO 1973/214
-#   http://www.canlii.org/en/yk/laws/regu/yco-1973-214/latest/yco-1973-214.html
+#   https://www.canlii.org/en/yk/laws/regu/yco-1973-214/latest/yco-1973-214.html
 #   C.O. 1973/214 INTERPRETATION ACT ...
 #
 #     1. Effective October 28, 1973 Commissioner's Order 1967/59 is hereby
@@ -2031,7 +2068,7 @@
 #   http://? - no online source found
 #
 # * Yukon Daylight Saving Time, YOIC 1987/56
-#   http://www.canlii.org/en/yk/laws/regu/yoic-1987-56/latest/yoic-1987-56.html
+#   https://www.canlii.org/en/yk/laws/regu/yoic-1987-56/latest/yoic-1987-56.html
 #   O.I.C. 1987/056 INTERPRETATION ACT ...
 #
 #   In every year between
@@ -2043,7 +2080,7 @@
 #   Dated ... 9th day of March, A.D., 1987.
 #
 # * Yukon Daylight Saving Time 2006, YOIC 2006/127
-#   http://www.canlii.org/en/yk/laws/regu/yoic-2006-127/latest/yoic-2006-127.html
+#   https://www.canlii.org/en/yk/laws/regu/yoic-2006-127/latest/yoic-2006-127.html
 #   O.I.C. 2006/127 INTERPRETATION ACT ...
 #
 #     1. In Yukon each year the time for general purposes shall be 7 hours
@@ -2057,7 +2094,7 @@
 #     3. This order comes into force January 1, 2007.
 #
 # * Interpretation Act, RSY 2002, c 125
-# http://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html
+# https://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html
 
 # From Rives McDow (1999-09-04):
 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
@@ -2100,7 +2137,7 @@
 
 # From Michaela Rodrigue, writing in the
 # Nunatsiaq News (1999-11-19):
-# http://www.nunatsiaq.com/archives/nunavut991130/nvt91119_17.html
+# http://www.nunatsiaqonline.ca/archives/nunavut991130/nvt91119_17.html
 # Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
 # central - or Nunavut time - for government offices, and eastern time
 # for municipal offices and schools....  Igloolik [was similar but then]
@@ -2118,7 +2155,7 @@
 # Central Time and Southampton Island [in the Central zone] is not
 # required to use daylight savings.
 
-# From <http://www.nunatsiaq.com/archives/nunavut001130/nvt21110_02.html>
+# From <http://www.nunatsiaqonline.ca/archives/nunavut001130/nvt21110_02.html>
 # Nunavut now has two time zones (2000-11-10):
 # The Nunavut government would allow its employees in Kugluktuk and
 # Cambridge Bay to operate on central time year-round, putting them
@@ -2449,7 +2486,7 @@
 # http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/V2-101209.html
 #
 # Our page:
-# http://www.timeanddate.com/news/time/north-mexico-dst-change.html
+# https://www.timeanddate.com/news/time/north-mexico-dst-change.html
 
 # From Arthur David Olson (2010-01-20):
 # The page
@@ -2734,15 +2771,15 @@
 # Belize
 # Whitman entirely disagrees with Shanks; go with Shanks & Pottenger.
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Belize	1918	1942	-	Oct	Sun>=2	0:00	0:30	HD
-Rule	Belize	1919	1943	-	Feb	Sun>=9	0:00	0	S
-Rule	Belize	1973	only	-	Dec	 5	0:00	1:00	D
-Rule	Belize	1974	only	-	Feb	 9	0:00	0	S
-Rule	Belize	1982	only	-	Dec	18	0:00	1:00	D
-Rule	Belize	1983	only	-	Feb	12	0:00	0	S
+Rule	Belize	1918	1942	-	Oct	Sun>=2	0:00	0:30	-0530
+Rule	Belize	1919	1943	-	Feb	Sun>=9	0:00	0	CST
+Rule	Belize	1973	only	-	Dec	 5	0:00	1:00	CDT
+Rule	Belize	1974	only	-	Feb	 9	0:00	0	CST
+Rule	Belize	1982	only	-	Dec	18	0:00	1:00	CDT
+Rule	Belize	1983	only	-	Feb	12	0:00	0	CST
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Belize	-5:52:48 -	LMT	1912 Apr
-			-6:00	Belize	C%sT
+			-6:00	Belize	%s
 
 # Bermuda
 
@@ -2868,7 +2905,7 @@
 # http://www.nnc.cubaweb.cu/marzo-2008/cien-1-11-3-08.htm
 #
 # Some more background information is posted here:
-# http://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
+# https://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
 #
 # The article also says that Cuba has been observing DST since 1963,
 # while Shanks (and tzdata) has 1965 as the first date (except in the
@@ -2915,7 +2952,7 @@
 # http://granma.co.cu/2011/03/08/nacional/artic01.html
 #
 # Our info:
-# http://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
+# https://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
 #
 # From Steffen Thorsen (2011-10-30)
 # Cuba will end DST two weeks later this year. Instead of going back
@@ -2925,7 +2962,7 @@
 # http://www.radioangulo.cu/noticias/cuba/17105-cuba-restablecera-el-horario-del-meridiano-de-greenwich.html
 #
 # Our page:
-# http://www.timeanddate.com/news/time/cuba-time-changes-2011.html
+# https://www.timeanddate.com/news/time/cuba-time-changes-2011.html
 #
 # From Steffen Thorsen (2012-03-01)
 # According to Radio Reloj, Cuba will start DST on Midnight between March
@@ -2935,7 +2972,7 @@
 # http://www.radioreloj.cu/index.php/noticias-radio-reloj/71-miscelaneas/7529-cuba-aplicara-el-horario-de-verano-desde-el-1-de-abril
 #
 # Our info on it:
-# http://www.timeanddate.com/news/time/cuba-starts-dst-2012.html
+# https://www.timeanddate.com/news/time/cuba-starts-dst-2012.html
 
 # From Steffen Thorsen (2012-11-03):
 # Radio Reloj and many other sources report that Cuba is changing back
@@ -3014,16 +3051,16 @@
 
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	DR	1966	only	-	Oct	30	0:00	1:00	D
-Rule	DR	1967	only	-	Feb	28	0:00	0	S
-Rule	DR	1969	1973	-	Oct	lastSun	0:00	0:30	HD
-Rule	DR	1970	only	-	Feb	21	0:00	0	S
-Rule	DR	1971	only	-	Jan	20	0:00	0	S
-Rule	DR	1972	1974	-	Jan	21	0:00	0	S
+Rule	DR	1966	only	-	Oct	30	0:00	1:00	EDT
+Rule	DR	1967	only	-	Feb	28	0:00	0	EST
+Rule	DR	1969	1973	-	Oct	lastSun	0:00	0:30	-0430
+Rule	DR	1970	only	-	Feb	21	0:00	0	EST
+Rule	DR	1971	only	-	Jan	20	0:00	0	EST
+Rule	DR	1972	1974	-	Jan	21	0:00	0	EST
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Santo_Domingo -4:39:36 -	LMT	1890
 			-4:40	-	SDMT	1933 Apr  1 12:00 # S. Dom. MT
-			-5:00	DR	E%sT	1974 Oct 27
+			-5:00	DR	%s	1974 Oct 27
 			-4:00	-	AST	2000 Oct 29  2:00
 			-5:00	US	E%sT	2000 Dec  3  1:00
 			-4:00	-	AST
@@ -3130,10 +3167,16 @@
 # From Steffen Thorsen (2016-03-12):
 # Jean Antoine, editor of www.haiti-reference.com informed us that Haiti
 # are not going on DST this year.  Several other resources confirm this: ...
-# http://www.radiotelevisioncaraibes.com/presse/heure_d_t_pas_de_changement_d_heure_pr_vu_pour_cet_ann_e.html
-# http://www.vantbefinfo.com/changement-dheure-pas-pour-haiti/
+# https://www.radiotelevisioncaraibes.com/presse/heure_d_t_pas_de_changement_d_heure_pr_vu_pour_cet_ann_e.html
+# https://www.vantbefinfo.com/changement-dheure-pas-pour-haiti/
 # http://news.anmwe.com/haiti-lheure-nationale-ne-sera-ni-avancee-ni-reculee-cette-annee/
 
+# From Steffen Thorsen (2017-03-12):
+# We have received 4 mails from different people telling that Haiti
+# has started DST again today, and this source seems to confirm that,
+# I have not been able to find a more authoritative source:
+# https://www.haitilibre.com/en/news-20319-haiti-notices-time-change-in-haiti.html
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Haiti	1983	only	-	May	8	0:00	1:00	D
 Rule	Haiti	1984	1987	-	Apr	lastSun	0:00	1:00	D
@@ -3146,6 +3189,8 @@
 Rule	Haiti	2005	2006	-	Oct	lastSun	0:00	0	S
 Rule	Haiti	2012	2015	-	Mar	Sun>=8	2:00	1:00	D
 Rule	Haiti	2012	2015	-	Nov	Sun>=1	2:00	0	S
+Rule	Haiti	2017	max	-	Mar	Sun>=8	2:00	1:00	D
+Rule	Haiti	2017	max	-	Nov	Sun>=1	2:00	0	S
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Port-au-Prince -4:49:20 -	LMT	1890
 			-4:49	-	PPMT	1917 Jan 24 12:00 # P-a-P MT
@@ -3313,8 +3358,8 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Miquelon	-3:44:40 -	LMT	1911 May 15 # St Pierre
 			-4:00	-	AST	1980 May
-			-3:00	-	PMST	1987 # Pierre & Miquelon Time
-			-3:00	Canada	PM%sT
+			-3:00	-	-03	1987
+			-3:00	Canada	-03/-02
 
 # St Vincent and the Grenadines
 # See America/Port_of_Spain.
@@ -3322,7 +3367,7 @@
 # Turks and Caicos
 #
 # From Chris Dunn in
-# http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=415007
+# https://bugs.debian.org/415007
 # (2007-03-15): In the Turks & Caicos Islands (America/Grand_Turk) the
 # daylight saving dates for time changes have been adjusted to match
 # the recent U.S. change of dates.
@@ -3344,12 +3389,25 @@
 # "permanent daylight saving time" by one year....
 # http://tcweeklynews.com/time-change-to-go-ahead-this-november-p5437-127.htm
 #
+# From the Turks & Caicos Cabinet (2017-07-20), heads-up from Steffen Thorsen:
+# ... agreed to the reintroduction in TCI of Daylight Saving Time (DST)
+# during the summer months and Standard Time, also known as Local
+# Time, during the winter months with effect from April 2018 ...
+# https://www.gov.uk/government/news/turks-and-caicos-post-cabinet-meeting-statement--3
+#
+# From Paul Eggert (2017-08-26):
+# The date of effect of the spring 2018 change appears to be March 11,
+# which makes more sense.  See: Hamilton D. Time change back
+# by March 2018 for TCI. Magnetic Media. 2017-08-25.
+# http://magneticmediatv.com/2017/08/time-change-back-by-march-2018-for-tci/
+#
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Grand_Turk	-4:44:32 -	LMT	1890
 			-5:07:11 -	KMT	1912 Feb # Kingston Mean Time
 			-5:00	-	EST	1979
 			-5:00	US	E%sT	2015 Nov Sun>=1 2:00
-			-4:00	-	AST
+			-4:00	-	AST	2018 Mar 11 3:00
+			-5:00	US	E%sT
 
 # British Virgin Is
 # Virgin Is
--- contrib/tzdata/southamerica.orig
+++ contrib/tzdata/southamerica
@@ -6,7 +6,7 @@
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
-# From Paul Eggert (2014-10-31):
+# From Paul Eggert (2016-12-05):
 #
 # Unless otherwise specified, the source for data through 1990 is:
 # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
@@ -13,8 +13,8 @@
 # San Diego: ACS Publications, Inc. (2003).
 # Unfortunately this book contains many errors and cites no sources.
 #
-# Gwillim Law writes that a good source
-# for recent time zone data is the International Air Transport
+# Many years ago Gwillim Law wrote that a good source
+# for time zone data was the International Air Transport
 # Association's Standard Schedules Information Manual (IATA SSIM),
 # published semiannually.  Law sent in several helpful summaries
 # of the IATA's data after 1990.  Except where otherwise noted,
@@ -22,34 +22,12 @@
 #
 # For data circa 1899, a common source is:
 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
-# http://www.jstor.org/stable/1774359
+# https://www.jstor.org/stable/1774359
 #
-# Earlier editions of these tables used the North American style (e.g. ARST and
-# ARDT for Argentine Standard and Daylight Time), but the following quote
-# suggests that it's better to use European style (e.g. ART and ARST).
-#	I suggest the use of _Summer time_ instead of the more cumbersome
-#	_daylight-saving time_.  _Summer time_ seems to be in general use
-#	in Europe and South America.
-#	-- E O Cutler, _New York Times_ (1937-02-14), quoted in
-#	H L Mencken, _The American Language: Supplement I_ (1960), p 466
-#
-# Earlier editions of these tables also used the North American style
-# for time zones in Brazil, but this was incorrect, as Brazilians say
-# "summer time".  Reinaldo Goulart, a São Paulo businessman active in
-# the railroad sector, writes (1999-07-06):
-#	The subject of time zones is currently a matter of discussion/debate in
-#	Brazil.  Let's say that "the Brasília time" is considered the
-#	"official time" because Brasília is the capital city.
-#	The other three time zones are called "Brasília time "minus one" or
-#	"plus one" or "plus two".  As far as I know there is no such
-#	name/designation as "Eastern Time" or "Central Time".
-# So I invented the following (English-language) abbreviations for now.
-# Corrections are welcome!
-#		std	dst
-#	-2:00	FNT	FNST	Fernando de Noronha
-#	-3:00	BRT	BRST	Brasília
-#	-4:00	AMT	AMST	Amazon
-#	-5:00	ACT	ACST	Acre
+# These tables use numeric abbreviations like -03 and -0330 for
+# integer hour and minute UTC offsets.  Although earlier editions used
+# alphabetic time zone abbreviations, these abbreviations were
+# invented and did not reflect common practice.
 
 ###############################################################################
 
@@ -287,8 +265,8 @@
 #
 # Es inminente que en San Luis atrasen una hora los relojes
 # (It is imminent in San Luis clocks one hour delay)
-# http://www.lagaceta.com.ar/nota/253414/Economia/Es-inminente-que-en-San-Luis-atrasen-una-hora-los-relojes.html
-# http://www.worldtimezone.net/dst_news/dst_news_argentina02.html
+# https://www.lagaceta.com.ar/nota/253414/Economia/Es-inminente-que-en-San-Luis-atrasen-una-hora-los-relojes.html
+# http://www.worldtimezone.com/dst_news/dst_news_argentina02.html
 
 # From Jesper Nørgaard Welen (2008-01-18):
 # The page of the San Luis provincial government
@@ -384,12 +362,6 @@
 #
 # So I guess a new set of rules, besides "Arg", must be made and the last
 # America/Argentina/San_Luis entries should change to use these...
-#
-# I'm enclosing a patch that does what I say... regretfully, the San Luis
-# timezone must be called "WART/WARST" even when most of the time (like,
-# right now) WARST == ART... that is, since last Sunday, all the country
-# is using UTC-3, but in my patch, San Luis calls it "WARST" and the rest
-# of the country calls it "ART".
 # ...
 
 # From Alexander Krivenyshev (2010-04-09):
@@ -413,7 +385,7 @@
 # Perhaps San Luis operates on the legal fiction that it is at -04
 # with perpetual summer time, but ordinary usage typically seems to
 # just say it's at -03; see, for example,
-# http://es.wikipedia.org/wiki/Hora_oficial_argentina
+# https://es.wikipedia.org/wiki/Hora_oficial_argentina
 # We've documented similar situations as being plain changes to
 # standard time, so let's do that here too.  This does not change UTC
 # offsets, only tm_isdst and the time zone abbreviations.  One minor
@@ -428,11 +400,11 @@
 # Buenos Aires (BA), Capital Federal (CF),
 Zone America/Argentina/Buenos_Aires -3:53:48 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May    # Córdoba Mean Time
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	Arg	AR%sT
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	Arg	-03/-02
 #
 # Córdoba (CB), Santa Fe (SF), Entre Ríos (ER), Corrientes (CN), Misiones (MN),
 # Chaco (CC), Formosa (FM), Santiago del Estero (SE)
@@ -446,113 +418,113 @@
 #
 Zone America/Argentina/Cordoba -4:16:48 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  3
-			-4:00	-	WART	1991 Oct 20
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	Arg	AR%sT
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  3
+			-4:00	-	-04	1991 Oct 20
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	Arg	-03/-02
 #
 # Salta (SA), La Pampa (LP), Neuquén (NQ), Rio Negro (RN)
 Zone America/Argentina/Salta -4:21:40 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  3
-			-4:00	-	WART	1991 Oct 20
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  3
+			-4:00	-	-04	1991 Oct 20
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # Tucumán (TM)
 Zone America/Argentina/Tucuman -4:20:52 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  3
-			-4:00	-	WART	1991 Oct 20
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 Jun  1
-			-4:00	-	WART	2004 Jun 13
-			-3:00	Arg	AR%sT
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  3
+			-4:00	-	-04	1991 Oct 20
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 Jun  1
+			-4:00	-	-04	2004 Jun 13
+			-3:00	Arg	-03/-02
 #
 # La Rioja (LR)
 Zone America/Argentina/La_Rioja -4:27:24 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  1
-			-4:00	-	WART	1991 May  7
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 Jun  1
-			-4:00	-	WART	2004 Jun 20
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  1
+			-4:00	-	-04	1991 May  7
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 Jun  1
+			-4:00	-	-04	2004 Jun 20
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # San Juan (SJ)
 Zone America/Argentina/San_Juan -4:34:04 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  1
-			-4:00	-	WART	1991 May  7
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 May 31
-			-4:00	-	WART	2004 Jul 25
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  1
+			-4:00	-	-04	1991 May  7
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 May 31
+			-4:00	-	-04	2004 Jul 25
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # Jujuy (JY)
 Zone America/Argentina/Jujuy -4:21:12 -	LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1990 Mar  4
-			-4:00	-	WART	1990 Oct 28
-			-4:00	1:00	WARST	1991 Mar 17
-			-4:00	-	WART	1991 Oct  6
-			-3:00	1:00	ARST	1992
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1990 Mar  4
+			-4:00	-	-04	1990 Oct 28
+			-4:00	1:00	-03	1991 Mar 17
+			-4:00	-	-04	1991 Oct  6
+			-3:00	1:00	-02	1992
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # Catamarca (CT), Chubut (CH)
 Zone America/Argentina/Catamarca -4:23:08 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1991 Mar  3
-			-4:00	-	WART	1991 Oct 20
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 Jun  1
-			-4:00	-	WART	2004 Jun 20
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1991 Mar  3
+			-4:00	-	-04	1991 Oct 20
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 Jun  1
+			-4:00	-	-04	2004 Jun 20
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # Mendoza (MZ)
 Zone America/Argentina/Mendoza -4:35:16 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1990 Mar  4
-			-4:00	-	WART	1990 Oct 15
-			-4:00	1:00	WARST	1991 Mar  1
-			-4:00	-	WART	1991 Oct 15
-			-4:00	1:00	WARST	1992 Mar  1
-			-4:00	-	WART	1992 Oct 18
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 May 23
-			-4:00	-	WART	2004 Sep 26
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1990 Mar  4
+			-4:00	-	-04	1990 Oct 15
+			-4:00	1:00	-03	1991 Mar  1
+			-4:00	-	-04	1991 Oct 15
+			-4:00	1:00	-03	1992 Mar  1
+			-4:00	-	-04	1992 Oct 18
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 May 23
+			-4:00	-	-04	2004 Sep 26
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # San Luis (SL)
 
@@ -561,44 +533,44 @@
 
 Zone America/Argentina/San_Luis -4:25:24 - LMT	1894 Oct 31
 			-4:16:48 -	CMT	1920 May
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1990
-			-3:00	1:00	ARST	1990 Mar 14
-			-4:00	-	WART	1990 Oct 15
-			-4:00	1:00	WARST	1991 Mar  1
-			-4:00	-	WART	1991 Jun  1
-			-3:00	-	ART	1999 Oct  3
-			-4:00	1:00	WARST	2000 Mar  3
-			-3:00	-	ART	2004 May 31
-			-4:00	-	WART	2004 Jul 25
-			-3:00	Arg	AR%sT	2008 Jan 21
-			-4:00	SanLuis	WAR%sT	2009 Oct 11
-			-3:00	-	ART
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1990
+			-3:00	1:00	-02	1990 Mar 14
+			-4:00	-	-04	1990 Oct 15
+			-4:00	1:00	-03	1991 Mar  1
+			-4:00	-	-04	1991 Jun  1
+			-3:00	-	-03	1999 Oct  3
+			-4:00	1:00	-03	2000 Mar  3
+			-3:00	-	-03	2004 May 31
+			-4:00	-	-04	2004 Jul 25
+			-3:00	Arg	-03/-02	2008 Jan 21
+			-4:00	SanLuis	-04/-03	2009 Oct 11
+			-3:00	-	-03
 #
 # Santa Cruz (SC)
 Zone America/Argentina/Rio_Gallegos -4:36:52 - LMT	1894 Oct 31
-			-4:16:48 -	CMT	1920 May    # Córdoba Mean Time
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 Jun  1
-			-4:00	-	WART	2004 Jun 20
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:16:48 -	CMT	1920 May
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 Jun  1
+			-4:00	-	-04	2004 Jun 20
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 #
 # Tierra del Fuego, Antártida e Islas del Atlántico Sur (TF)
 Zone America/Argentina/Ushuaia -4:33:12 - LMT	1894 Oct 31
-			-4:16:48 -	CMT	1920 May    # Córdoba Mean Time
-			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1999 Oct  3
-			-4:00	Arg	AR%sT	2000 Mar  3
-			-3:00	-	ART	2004 May 30
-			-4:00	-	WART	2004 Jun 20
-			-3:00	Arg	AR%sT	2008 Oct 18
-			-3:00	-	ART
+			-4:16:48 -	CMT	1920 May
+			-4:00	-	-04	1930 Dec
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1999 Oct  3
+			-4:00	Arg	-04/-03	2000 Mar  3
+			-3:00	-	-03	2004 May 30
+			-4:00	-	-04	2004 Jun 20
+			-3:00	Arg	-03/-02	2008 Oct 18
+			-3:00	-	-03
 
 # Aruba
 Link America/Curacao America/Aruba
@@ -608,7 +580,7 @@
 Zone	America/La_Paz	-4:32:36 -	LMT	1890
 			-4:32:36 -	CMT	1931 Oct 15 # Calamarca MT
 			-4:32:36 1:00	BOST	1932 Mar 21 # Bolivia ST
-			-4:00	-	BOT	# Bolivia Time
+			-4:00	-	-04
 
 # Brazil
 
@@ -744,7 +716,7 @@
 # (Portuguese)
 #
 # We have a written a short article about it as well:
-# http://www.timeanddate.com/news/time/brazil-dst-2008-2009.html
+# https://www.timeanddate.com/news/time/brazil-dst-2008-2009.html
 #
 # From Alexander Krivenyshev (2011-10-04):
 # State Bahia will return to Daylight savings time this year after 8 years off.
@@ -753,7 +725,7 @@
 
 # In Portuguese:
 # http://g1.globo.com/bahia/noticia/2011/10/governador-jaques-wagner-confirma-horario-de-verao-na-bahia.html
-# http://noticias.terra.com.br/brasil/noticias/0,,OI5390887-EI8139,00-Bahia+volta+a+ter+horario+de+verao+apos+oito+anos.html
+# https://noticias.terra.com.br/brasil/noticias/0,,OI5390887-EI8139,00-Bahia+volta+a+ter+horario+de+verao+apos+oito+anos.html
 
 # From Guilherme Bernardes Rodrigues (2011-10-07):
 # There is news in the media, however there is still no decree about it.
@@ -779,16 +751,16 @@
 
 # From Rodrigo Severo (2012-10-16):
 # Tocantins state will have DST.
-# http://noticias.terra.com.br/brasil/noticias/0,,OI6232536-EI306.html
+# https://noticias.terra.com.br/brasil/noticias/0,,OI6232536-EI306.html
 
 # From Steffen Thorsen (2013-09-20):
 # Tocantins in Brazil is very likely not to observe DST from October....
 # http://conexaoto.com.br/2013/09/18/ministerio-confirma-que-tocantins-esta-fora-do-horario-de-verao-em-2013-mas-falta-publicacao-de-decreto
 # We will keep this article updated when this is confirmed:
-# http://www.timeanddate.com/news/time/brazil-starts-dst-2013.html
+# https://www.timeanddate.com/news/time/brazil-starts-dst-2013.html
 
 # From Steffen Thorsen (2013-10-17):
-# http://www.timeanddate.com/news/time/acre-amazonas-change-time-zone.html
+# https://www.timeanddate.com/news/time/acre-amazonas-change-time-zone.html
 # Senator Jorge Viana announced that Acre will change time zone on November 10.
 # He did not specify the time of the change, nor if western parts of Amazonas
 # will change as well.
@@ -960,12 +932,12 @@
 #
 # Fernando de Noronha (administratively part of PE)
 Zone America/Noronha	-2:09:40 -	LMT	1914
-			-2:00	Brazil	FN%sT	1990 Sep 17
-			-2:00	-	FNT	1999 Sep 30
-			-2:00	Brazil	FN%sT	2000 Oct 15
-			-2:00	-	FNT	2001 Sep 13
-			-2:00	Brazil	FN%sT	2002 Oct  1
-			-2:00	-	FNT
+			-2:00	Brazil	-02/-01	1990 Sep 17
+			-2:00	-	-02	1999 Sep 30
+			-2:00	Brazil	-02/-01	2000 Oct 15
+			-2:00	-	-02	2001 Sep 13
+			-2:00	Brazil	-02/-01	2002 Oct  1
+			-2:00	-	-02
 # Other Atlantic islands have no permanent settlement.
 # These include Trindade and Martim Vaz (administratively part of ES),
 # Rocas Atoll (RN), and the St Peter and St Paul Archipelago (PE).
@@ -978,119 +950,119 @@
 # In the north a very small part from the river Javary (now Jari I guess,
 # the border with Amapá) to the Amazon, then to the Xingu.
 Zone America/Belem	-3:13:56 -	LMT	1914
-			-3:00	Brazil	BR%sT	1988 Sep 12
-			-3:00	-	BRT
+			-3:00	Brazil	-03/-02	1988 Sep 12
+			-3:00	-	-03
 #
 # west Pará (PA)
 # West Pará includes Altamira, Óbidos, Prainha, Oriximiná, and Santarém.
 Zone America/Santarem	-3:38:48 -	LMT	1914
-			-4:00	Brazil	AM%sT	1988 Sep 12
-			-4:00	-	AMT	2008 Jun 24  0:00
-			-3:00	-	BRT
+			-4:00	Brazil	-04/-03	1988 Sep 12
+			-4:00	-	-04	2008 Jun 24  0:00
+			-3:00	-	-03
 #
 # Maranhão (MA), Piauí (PI), Ceará (CE), Rio Grande do Norte (RN),
 # Paraíba (PB)
 Zone America/Fortaleza	-2:34:00 -	LMT	1914
-			-3:00	Brazil	BR%sT	1990 Sep 17
-			-3:00	-	BRT	1999 Sep 30
-			-3:00	Brazil	BR%sT	2000 Oct 22
-			-3:00	-	BRT	2001 Sep 13
-			-3:00	Brazil	BR%sT	2002 Oct  1
-			-3:00	-	BRT
+			-3:00	Brazil	-03/-02	1990 Sep 17
+			-3:00	-	-03	1999 Sep 30
+			-3:00	Brazil	-03/-02	2000 Oct 22
+			-3:00	-	-03	2001 Sep 13
+			-3:00	Brazil	-03/-02	2002 Oct  1
+			-3:00	-	-03
 #
 # Pernambuco (PE) (except Atlantic islands)
 Zone America/Recife	-2:19:36 -	LMT	1914
-			-3:00	Brazil	BR%sT	1990 Sep 17
-			-3:00	-	BRT	1999 Sep 30
-			-3:00	Brazil	BR%sT	2000 Oct 15
-			-3:00	-	BRT	2001 Sep 13
-			-3:00	Brazil	BR%sT	2002 Oct  1
-			-3:00	-	BRT
+			-3:00	Brazil	-03/-02	1990 Sep 17
+			-3:00	-	-03	1999 Sep 30
+			-3:00	Brazil	-03/-02	2000 Oct 15
+			-3:00	-	-03	2001 Sep 13
+			-3:00	Brazil	-03/-02	2002 Oct  1
+			-3:00	-	-03
 #
 # Tocantins (TO)
 Zone America/Araguaina	-3:12:48 -	LMT	1914
-			-3:00	Brazil	BR%sT	1990 Sep 17
-			-3:00	-	BRT	1995 Sep 14
-			-3:00	Brazil	BR%sT	2003 Sep 24
-			-3:00	-	BRT	2012 Oct 21
-			-3:00	Brazil	BR%sT	2013 Sep
-			-3:00	-	BRT
+			-3:00	Brazil	-03/-02	1990 Sep 17
+			-3:00	-	-03	1995 Sep 14
+			-3:00	Brazil	-03/-02	2003 Sep 24
+			-3:00	-	-03	2012 Oct 21
+			-3:00	Brazil	-03/-02	2013 Sep
+			-3:00	-	-03
 #
 # Alagoas (AL), Sergipe (SE)
 Zone America/Maceio	-2:22:52 -	LMT	1914
-			-3:00	Brazil	BR%sT	1990 Sep 17
-			-3:00	-	BRT	1995 Oct 13
-			-3:00	Brazil	BR%sT	1996 Sep  4
-			-3:00	-	BRT	1999 Sep 30
-			-3:00	Brazil	BR%sT	2000 Oct 22
-			-3:00	-	BRT	2001 Sep 13
-			-3:00	Brazil	BR%sT	2002 Oct  1
-			-3:00	-	BRT
+			-3:00	Brazil	-03/-02	1990 Sep 17
+			-3:00	-	-03	1995 Oct 13
+			-3:00	Brazil	-03/-02	1996 Sep  4
+			-3:00	-	-03	1999 Sep 30
+			-3:00	Brazil	-03/-02	2000 Oct 22
+			-3:00	-	-03	2001 Sep 13
+			-3:00	Brazil	-03/-02	2002 Oct  1
+			-3:00	-	-03
 #
 # Bahia (BA)
 # There are too many Salvadors elsewhere, so use America/Bahia instead
 # of America/Salvador.
 Zone America/Bahia	-2:34:04 -	LMT	1914
-			-3:00	Brazil	BR%sT	2003 Sep 24
-			-3:00	-	BRT	2011 Oct 16
-			-3:00	Brazil	BR%sT	2012 Oct 21
-			-3:00	-	BRT
+			-3:00	Brazil	-03/-02	2003 Sep 24
+			-3:00	-	-03	2011 Oct 16
+			-3:00	Brazil	-03/-02	2012 Oct 21
+			-3:00	-	-03
 #
 # Goiás (GO), Distrito Federal (DF), Minas Gerais (MG),
 # Espírito Santo (ES), Rio de Janeiro (RJ), São Paulo (SP), Paraná (PR),
 # Santa Catarina (SC), Rio Grande do Sul (RS)
 Zone America/Sao_Paulo	-3:06:28 -	LMT	1914
-			-3:00	Brazil	BR%sT	1963 Oct 23  0:00
-			-3:00	1:00	BRST	1964
-			-3:00	Brazil	BR%sT
+			-3:00	Brazil	-03/-02	1963 Oct 23  0:00
+			-3:00	1:00	-02	1964
+			-3:00	Brazil	-03/-02
 #
 # Mato Grosso do Sul (MS)
 Zone America/Campo_Grande -3:38:28 -	LMT	1914
-			-4:00	Brazil	AM%sT
+			-4:00	Brazil	-04/-03
 #
 # Mato Grosso (MT)
 Zone America/Cuiaba	-3:44:20 -	LMT	1914
-			-4:00	Brazil	AM%sT	2003 Sep 24
-			-4:00	-	AMT	2004 Oct  1
-			-4:00	Brazil	AM%sT
+			-4:00	Brazil	-04/-03	2003 Sep 24
+			-4:00	-	-04	2004 Oct  1
+			-4:00	Brazil	-04/-03
 #
 # Rondônia (RO)
 Zone America/Porto_Velho -4:15:36 -	LMT	1914
-			-4:00	Brazil	AM%sT	1988 Sep 12
-			-4:00	-	AMT
+			-4:00	Brazil	-04/-03	1988 Sep 12
+			-4:00	-	-04
 #
 # Roraima (RR)
 Zone America/Boa_Vista	-4:02:40 -	LMT	1914
-			-4:00	Brazil	AM%sT	1988 Sep 12
-			-4:00	-	AMT	1999 Sep 30
-			-4:00	Brazil	AM%sT	2000 Oct 15
-			-4:00	-	AMT
+			-4:00	Brazil	-04/-03	1988 Sep 12
+			-4:00	-	-04	1999 Sep 30
+			-4:00	Brazil	-04/-03	2000 Oct 15
+			-4:00	-	-04
 #
 # east Amazonas (AM): Boca do Acre, Jutaí, Manaus, Floriano Peixoto
 # The great circle line from Tabatinga to Porto Acre divides
 # east from west Amazonas.
 Zone America/Manaus	-4:00:04 -	LMT	1914
-			-4:00	Brazil	AM%sT	1988 Sep 12
-			-4:00	-	AMT	1993 Sep 28
-			-4:00	Brazil	AM%sT	1994 Sep 22
-			-4:00	-	AMT
+			-4:00	Brazil	-04/-03	1988 Sep 12
+			-4:00	-	-04	1993 Sep 28
+			-4:00	Brazil	-04/-03	1994 Sep 22
+			-4:00	-	-04
 #
 # west Amazonas (AM): Atalaia do Norte, Boca do Maoco, Benjamin Constant,
 #	Eirunepé, Envira, Ipixuna
 Zone America/Eirunepe	-4:39:28 -	LMT	1914
-			-5:00	Brazil	AC%sT	1988 Sep 12
-			-5:00	-	ACT	1993 Sep 28
-			-5:00	Brazil	AC%sT	1994 Sep 22
-			-5:00	-	ACT	2008 Jun 24  0:00
-			-4:00	-	AMT	2013 Nov 10
-			-5:00	-	ACT
+			-5:00	Brazil	-05/-04	1988 Sep 12
+			-5:00	-	-05	1993 Sep 28
+			-5:00	Brazil	-05/-04	1994 Sep 22
+			-5:00	-	-05	2008 Jun 24  0:00
+			-4:00	-	-04	2013 Nov 10
+			-5:00	-	-05
 #
 # Acre (AC)
 Zone America/Rio_Branco	-4:31:12 -	LMT	1914
-			-5:00	Brazil	AC%sT	1988 Sep 12
-			-5:00	-	ACT	2008 Jun 24  0:00
-			-4:00	-	AMT	2013 Nov 10
-			-5:00	-	ACT
+			-5:00	Brazil	-05/-04	1988 Sep 12
+			-5:00	-	-05	2008 Jun 24  0:00
+			-4:00	-	-04	2013 Nov 10
+			-5:00	-	-05
 
 # Chile
 
@@ -1104,18 +1076,18 @@
 # the following source, cited by Oscar van Vlijmen (2006-10-08):
 # [1] Chile Law
 # http://www.webexhibits.org/daylightsaving/chile.html
-# This contains a copy of a this official table:
+# This contains a copy of this official table:
 # Cambios en la hora oficial de Chile desde 1900 (retrieved 2008-03-30)
-# http://web.archive.org/web/20080330200901/http://www.horaoficial.cl/cambio.htm
+# https://web.archive.org/web/20080330200901/http://www.horaoficial.cl/cambio.htm
 # [1] needs several corrections, though.
 #
 # The first set of corrections is from:
 # [2] History of the Official Time of Chile
 # http://www.horaoficial.cl/ing/horaof_ing.html (retrieved 2012-03-06).  See:
-# http://web.archive.org/web/20120306042032/http://www.horaoficial.cl/ing/horaof_ing.html
+# https://web.archive.org/web/20120306042032/http://www.horaoficial.cl/ing/horaof_ing.html
 # This is an English translation of:
 # Historia de la hora oficial de Chile (retrieved 2012-10-24).  See:
-# http://web.archive.org/web/20121024234627/http://www.horaoficial.cl/horaof.htm
+# https://web.archive.org/web/20121024234627/http://www.horaoficial.cl/horaof.htm
 # A fancier Spanish version (requiring mouse-clicking) is at:
 # http://www.horaoficial.cl/historia_hora.html
 # Conflicts between [1] and [2] were resolved as follows:
@@ -1235,6 +1207,18 @@
 # to mean 24:00 mainland time, not 24:00 local time, so that Easter
 # Island is always two hours behind the mainland.
 
+# From Juan Correa (2016-12-04):
+# Magallanes region ... will keep DST (UTC -3) all year round....
+# http://www.soychile.cl/Santiago/Sociedad/2016/12/04/433428/Bachelet-firmo-el-decreto-para-establecer-un-horario-unico-para-la-Region-de-Magallanes.aspx
+#
+# From Deborah Goldsmith (2017-01-19):
+# http://www.diariooficial.interior.gob.cl/publicaciones/2017/01/17/41660/01/1169626.pdf
+# From Paul Eggert (2017-01-19):
+# The above says the Magallanes change expires 2019-05-11 at 24:00,
+# so in theory, they will revert to -04/-03 after that, which means
+# they will switch from -03 to -04 one hour after Santiago does that day.
+# For now, assume that they will not revert.
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Chile	1927	1931	-	Sep	 1	0:00	1:00	S
 Rule	Chile	1928	1932	-	Apr	 1	0:00	0	-
@@ -1275,22 +1259,35 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Santiago	-4:42:46 -	LMT	1890
 			-4:42:46 -	SMT	1910 Jan 10 # Santiago Mean Time
-			-5:00	-	CLT	1916 Jul  1 # Chile Time
+			-5:00	-	-05	1916 Jul  1
 			-4:42:46 -	SMT	1918 Sep 10
-			-4:00	-	CLT	1919 Jul  1
+			-4:00	-	-04	1919 Jul  1
 			-4:42:46 -	SMT	1927 Sep  1
-			-5:00	Chile	CL%sT	1932 Sep  1
-			-4:00	-	CLT	1942 Jun  1
-			-5:00	-	CLT	1942 Aug  1
-			-4:00	-	CLT	1946 Jul 15
-			-4:00	1:00	CLST	1946 Sep  1 # central Chile
-			-4:00	-	CLT	1947 Apr  1
-			-5:00	-	CLT	1947 May 21 23:00
-			-4:00	Chile	CL%sT
+			-5:00	Chile	-05/-04	1932 Sep  1
+			-4:00	-	-04	1942 Jun  1
+			-5:00	-	-05	1942 Aug  1
+			-4:00	-	-04	1946 Jul 15
+			-4:00	1:00	-03	1946 Sep  1 # central Chile
+			-4:00	-	-04	1947 Apr  1
+			-5:00	-	-05	1947 May 21 23:00
+			-4:00	Chile	-04/-03
+Zone America/Punta_Arenas -4:43:40 -	LMT	1890
+			-4:42:46 -	SMT	1910 Jan 10
+			-5:00	-	-05	1916 Jul  1
+			-4:42:46 -	SMT	1918 Sep 10
+			-4:00	-	-04	1919 Jul  1
+			-4:42:46 -	SMT	1927 Sep  1
+			-5:00	Chile	-05/-04	1932 Sep  1
+			-4:00	-	-04	1942 Jun  1
+			-5:00	-	-05	1942 Aug  1
+			-4:00	-	-04	1947 Apr  1
+			-5:00	-	-05	1947 May 21 23:00
+			-4:00	Chile	-04/-03	2016 Dec  4
+			-3:00	-	-03
 Zone Pacific/Easter	-7:17:28 -	LMT	1890
 			-7:17:28 -	EMT	1932 Sep    # Easter Mean Time
-			-7:00	Chile	EAS%sT	1982 Mar 14 3:00u # Easter Time
-			-6:00	Chile	EAS%sT
+			-7:00	Chile	-07/-06	1982 Mar 14 3:00u # Easter Time
+			-6:00	Chile	-06/-05
 #
 # Salas y Gómez Island is uninhabited.
 # Other Chilean locations, including Juan Fernández Is, Desventuradas Is,
@@ -1310,9 +1307,10 @@
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Antarctica/Palmer	0	-	-00	1965
-			-4:00	Arg	AR%sT	1969 Oct  5
-			-3:00	Arg	AR%sT	1982 May
-			-4:00	Chile	CL%sT
+			-4:00	Arg	-04/-03	1969 Oct  5
+			-3:00	Arg	-03/-02	1982 May
+			-4:00	Chile	-04/-03	2016 Dec  4
+			-3:00	-	-03
 
 # Colombia
 
@@ -1325,7 +1323,7 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Bogota	-4:56:16 -	LMT	1884 Mar 13
 			-4:56:16 -	BMT	1914 Nov 23 # Bogotá Mean Time
-			-5:00	CO	CO%sT	# Colombia Time
+			-5:00	CO	-05/-04
 # Malpelo, Providencia, San Andres
 # no information; probably like America/Bogota
 
@@ -1349,7 +1347,7 @@
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Curacao	-4:35:47 -	LMT	1912 Feb 12 # Willemstad
-			-4:30	-	ANT	1965 # Netherlands Antilles Time
+			-4:30	-	-0430	1965
 			-4:00	-	AST
 
 # From Arthur David Olson (2011-06-15):
@@ -1364,19 +1362,32 @@
 #
 # Milne says the Central and South American Telegraph Company used -5:24:15.
 #
-# From Paul Eggert (2007-03-04):
-# Apparently Ecuador had a failed experiment with DST in 1992.
-# <http://midena.gov.ec/content/view/1261/208/> (2007-02-27) and
-# <http://www.hoy.com.ec/NoticiaNue.asp?row_id=249856> (2006-11-06) both
-# talk about "hora Sixto".  Leave this alone for now, as we have no data.
+# From Alois Treindl (2016-12-15):
+# https://www.elcomercio.com/actualidad/hora-sixto-1993.html
+# ... Whether the law applied also to Galápagos, I do not know.
+# From Paul Eggert (2016-12-15):
+# https://www.elcomercio.com/afull/modificacion-husohorario-ecuador-presidentes-decreto.html
+# This says President Sixto Durán Ballén signed decree No. 285, which
+# established DST from 1992-11-28 to 1993-02-05; it does not give transition
+# times.  The people called it "hora de Sixto" ("Sixto hour").  The change did
+# not go over well; a popular song "Qué hora es" by Jaime Guevara had lyrics
+# that included "Amanecía en mitad de la noche, los guaguas iban a clase sin
+# sol" ("It was dawning in the middle of the night, the buses went to class
+# without sun").  Although Ballén's campaign slogan was "Ni un paso atrás"
+# (Not one step back), the clocks went back in 1993 and the experiment was not
+# repeated.  For now, assume transitions were at 00:00 local time country-wide.
 #
+# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
+Rule	Ecuador	1992	only	-	Nov	28	0:00	1:00	S
+Rule	Ecuador	1993	only	-	Feb	 5	0:00	0	-
+#
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Guayaquil	-5:19:20 -	LMT	1890
 			-5:14:00 -	QMT	1931 # Quito Mean Time
-			-5:00	-	ECT	# Ecuador Time
+			-5:00	Ecuador	-05/-04
 Zone Pacific/Galapagos	-5:58:24 -	LMT	1931 # Puerto Baquerizo Moreno
-			-5:00	-	ECT	1986
-			-6:00	-	GALT	# Galápagos Time
+			-5:00	-	-05	1986
+			-6:00	Ecuador	-06/-05
 
 # Falklands
 
@@ -1476,25 +1487,24 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Atlantic/Stanley	-3:51:24 -	LMT	1890
 			-3:51:24 -	SMT	1912 Mar 12 # Stanley Mean Time
-			-4:00	Falk	FK%sT	1983 May    # Falkland Is Time
-			-3:00	Falk	FK%sT	1985 Sep 15
-			-4:00	Falk	FK%sT	2010 Sep  5  2:00
-			-3:00	-	FKST
+			-4:00	Falk	-04/-03	1983 May
+			-3:00	Falk	-03/-02	1985 Sep 15
+			-4:00	Falk	-04/-03	2010 Sep  5  2:00
+			-3:00	-	-03
 
 # French Guiana
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Cayenne	-3:29:20 -	LMT	1911 Jul
-			-4:00	-	GFT	1967 Oct # French Guiana Time
-			-3:00	-	GFT
+			-4:00	-	-04	1967 Oct
+			-3:00	-	-03
 
 # Guyana
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Guyana	-3:52:40 -	LMT	1915 Mar    # Georgetown
-			-3:45	-	GBGT	1966 May 26 # Br Guiana Time
-			-3:45	-	GYT	1975 Jul 31 # Guyana Time
-			-3:00	-	GYT	1991
+			-3:45	-	-0345	1975 Jul 31
+			-3:00	-	-03	1991
 # IATA SSIM (1996-06) says -4:00.  Assume a 1991 switch.
-			-4:00	-	GYT
+			-4:00	-	-04
 
 # Paraguay
 #
@@ -1586,9 +1596,9 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Asuncion	-3:50:40 -	LMT	1890
 			-3:50:40 -	AMT	1931 Oct 10 # Asunción Mean Time
-			-4:00	-	PYT	1972 Oct    # Paraguay Time
-			-3:00	-	PYT	1974 Apr
-			-4:00	Para	PY%sT
+			-4:00	-	-04	1972 Oct
+			-3:00	-	-03	1974 Apr
+			-4:00	Para	-04/-03
 
 # Peru
 #
@@ -1615,12 +1625,12 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Lima	-5:08:12 -	LMT	1890
 			-5:08:36 -	LMT	1908 Jul 28 # Lima Mean Time?
-			-5:00	Peru	PE%sT	# Peru Time
+			-5:00	Peru	-05/-04
 
 # South Georgia
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Atlantic/South_Georgia -2:26:08 -	LMT	1890 # Grytviken
-			-2:00	-	GST	# South Georgia Time
+			-2:00	-	-02
 
 # South Sandwich Is
 # uninhabited; scientific personnel have wintered
@@ -1630,9 +1640,8 @@
 Zone America/Paramaribo	-3:40:40 -	LMT	1911
 			-3:40:52 -	PMT	1935     # Paramaribo Mean Time
 			-3:40:36 -	PMT	1945 Oct    # The capital moved?
-			-3:30	-	NEGT	1975 Nov 20 # Dutch Guiana Time
-			-3:30	-	SRT	1984 Oct    # Suriname Time
-			-3:00	-	SRT
+			-3:30	-	-0330	1984 Oct
+			-3:00	-	-03
 
 # Trinidad and Tobago
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
@@ -1735,11 +1744,16 @@
 # [dated 2015-06-29; repeals Decree 311/006 dated 2006-09-04]
 Rule	Uruguay	2006	2014	-	Oct	Sun>=1	 2:00	1:00	S
 Rule	Uruguay	2007	2015	-	Mar	Sun>=8	 2:00	0	-
-# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
+
+# This Zone can be simplified once we assume zic %z.
 Zone America/Montevideo	-3:44:44 -	LMT	1898 Jun 28
 			-3:44:44 -	MMT	1920 May  1 # Montevideo MT
-			-3:30	Uruguay	UY%sT	1942 Dec 14 # Uruguay Time
-			-3:00	Uruguay	UY%sT
+			-3:30	Uruguay	-0330/-03 1942 Dec 14
+			-3:00	Uruguay	-03/-02	1968
+			-3:00	Uruguay	-03/-0230 1971
+			-3:00	Uruguay	-03/-02	1974
+			-3:00	Uruguay	-03/-0230 1974 Dec 22
+			-3:00	Uruguay	-03/-02
 
 # Venezuela
 #
@@ -1764,7 +1778,7 @@
 # hours of presidential broadcasts, hours of lines,' quipped comedian
 # Jean Mary Curró ...". See: Cawthorne A, Kai D. Venezuela scraps
 # half-hour time difference set by Chavez. Reuters 2016-04-15 14:50 -0400
-# http://www.reuters.com/article/us-venezuela-timezone-idUSKCN0XC2BE
+# https://www.reuters.com/article/us-venezuela-timezone-idUSKCN0XC2BE
 #
 # From Matt Johnson (2016-04-20):
 # ... published in the official Gazette [2016-04-18], here:
@@ -1773,7 +1787,7 @@
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Caracas	-4:27:44 -	LMT	1890
 			-4:27:40 -	CMT	1912 Feb 12 # Caracas Mean Time?
-			-4:30	-	VET	1965 Jan  1  0:00 # Venezuela T.
-			-4:00	-	VET	2007 Dec  9  3:00
-			-4:30	-	VET	2016 May  1  2:30
-			-4:00	-	VET
+			-4:30	-	-0430	1965 Jan  1  0:00
+			-4:00	-	-04	2007 Dec  9  3:00
+			-4:30	-	-0430	2016 May  1  2:30
+			-4:00	-	-04
--- contrib/tzdata/theory.html.orig
+++ contrib/tzdata/theory.html
@@ -0,0 +1,1034 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>Theory and pragmatics of the tz code and data</title>
+  <meta charset="UTF-8">
+</head>
+
+<!-- The somewhat-unusal indenting style in this file is intended to
+     shrink the output of the shell command 'diff Theory Theory.html',
+     where 'Theory' was the plain text file that this file is derived
+     from.  The 'Theory' file used leading white space to indent, and
+     when possible that indentation is preserved here.  Eventually we
+     may stop doing this and remove this comment.  -->
+
+<body>
+  <h1>Theory and pragmatics of the tz code and data</h1>
+  <h3>Outline</h3>
+  <nav>
+    <ul>
+      <li><a href="#scope">Scope of the tz database</a></li>
+      <li><a href="#naming">Names of time zone rules</a></li>
+      <li><a href="#abbreviations">Time zone abbreviations</a></li>
+      <li><a href="#accuracy">Accuracy of the tz database</a></li>
+      <li><a href="#functions">Time and date functions</a></li>
+      <li><a href="#stability">Interface stability</a></li>
+      <li><a href="#calendar">Calendrical issues</a></li>
+      <li><a href="#planets">Time and time zones on other planets</a></li>
+    </ul>
+  </nav>
+
+
+  <section>
+    <h2 id="scope">Scope of the tz database</h2>
+<p>
+The tz database attempts to record the history and predicted future of
+all computer-based clocks that track civil time.  To represent this
+data, the world is partitioned into regions whose clocks all agree
+about timestamps that occur after the somewhat-arbitrary cutoff point
+of the POSIX Epoch (1970-01-01 00:00:00 UTC).  For each such region,
+the database records all known clock transitions, and labels the region
+with a notable location.  Although 1970 is a somewhat-arbitrary
+cutoff, there are significant challenges to moving the cutoff earlier
+even by a decade or two, due to the wide variety of local practices
+before computer timekeeping became prevalent.
+</p>
+
+<p>
+Clock transitions before 1970 are recorded for each such location,
+because most systems support timestamps before 1970 and could
+misbehave if data entries were omitted for pre-1970 transitions.
+However, the database is not designed for and does not suffice for
+applications requiring accurate handling of all past times everywhere,
+as it would take far too much effort and guesswork to record all
+details of pre-1970 civil timekeeping.
+</p>
+
+<p>
+As described below, reference source code for using the tz database is
+also available.  The tz code is upwards compatible with POSIX, an
+international standard for UNIX-like systems.  As of this writing, the
+current edition of POSIX is:
+  <a href="http://pubs.opengroup.org/onlinepubs/9699919799/">
+  The Open Group Base Specifications Issue 7</a>,
+  IEEE Std 1003.1-2008, 2016 Edition.
+</p>
+  </section>
+
+
+
+  <section>
+    <h2 id="naming">Names of time zone rules</h2>
+<p>
+Each of the database's time zone rules has a unique name.
+Inexperienced users are not expected to select these names unaided.
+Distributors should provide documentation and/or a simple selection
+interface that explains the names; for one example, see the 'tzselect'
+program in the tz code.  The
+<a href="http://cldr.unicode.org/">Unicode Common Locale Data
+Repository</a> contains data that may be useful for other
+selection interfaces.
+</p>
+
+<p>
+The time zone rule naming conventions attempt to strike a balance
+among the following goals:
+</p>
+<ul>
+  <li>
+   Uniquely identify every region where clocks have agreed since 1970.
+   This is essential for the intended use: static clocks keeping local
+   civil time.
+  </li>
+  <li>
+   Indicate to experts where that region is.
+  </li>
+  <li>
+   Be robust in the presence of political changes.  For example, names
+   of countries are ordinarily not used, to avoid incompatibilities
+   when countries change their name (e.g. Zaire&rarr;Congo) or when
+   locations change countries (e.g. Hong Kong from UK colony to
+   China).
+  </li>
+  <li>
+   Be portable to a wide variety of implementations.
+  </li>
+  <li>
+   Use a consistent naming conventions over the entire world.
+  </li>
+</ul>
+<p>
+Names normally have the
+form <var>AREA</var><code>/</code><var>LOCATION</var>,
+where <var>AREA</var> is the name of a continent or ocean,
+and <var>LOCATION</var> is the name of a specific
+location within that region.  North and South America share the same
+area, '<code>America</code>'.  Typical names are
+'<code>Africa/Cairo</code>', '<code>America/New_York</code>', and
+'<code>Pacific/Honolulu</code>'.
+</p>
+
+<p>
+Here are the general rules used for choosing location names,
+in decreasing order of importance:
+</p>
+<ul>
+  <li>
+	Use only valid POSIX file name components (i.e., the parts of
+		names other than '<code>/</code>').  Do not use the file name
+		components '<code>.</code>' and '<code>..</code>'.
+		Within a file name component,
+		use only ASCII letters, '<code>.</code>',
+		'<code>-</code>' and '<code>_</code>'.  Do not use
+		digits, as that might create an ambiguity with POSIX
+		TZ strings.  A file name component must not exceed 14
+		characters or start with '<code>-</code>'.  E.g.,
+		prefer '<code>Brunei</code>' to
+		'<code>Bandar_Seri_Begawan</code>'.  Exceptions: see
+		the discussion
+		of legacy names below.
+  </li>
+  <li>
+	A name must not be empty, or contain '<code>//</code>', or
+	start or end with '<code>/</code>'.
+  </li>
+  <li>
+	Do not use names that differ only in case.  Although the reference
+		implementation is case-sensitive, some other implementations
+		are not, and they would mishandle names differing only in case.
+  </li>
+  <li>
+	If one name <var>A</var> is an initial prefix of another
+		name <var>AB</var> (ignoring case), then <var>B</var>
+		must not start with '<code>/</code>', as a
+		regular file cannot have
+		the same name as a directory in POSIX.  For example,
+		'<code>America/New_York</code>' precludes
+		'<code>America/New_York/Bronx</code>'.
+  </li>
+  <li>
+	Uninhabited regions like the North Pole and Bouvet Island
+		do not need locations, since local time is not defined there.
+  </li>
+  <li>
+	There should typically be at least one name for each ISO 3166-1
+		officially assigned two-letter code for an inhabited country
+		or territory.
+  </li>
+  <li>
+	If all the clocks in a region have agreed since 1970,
+		don't bother to include more than one location
+		even if subregions' clocks disagreed before 1970.
+		Otherwise these tables would become annoyingly large.
+  </li>
+  <li>
+	If a name is ambiguous, use a less ambiguous alternative;
+		e.g. many cities are named San José and Georgetown, so
+		prefer '<code>Costa_Rica</code>' to '<code>San_Jose</code>' and '<code>Guyana</code>' to '<code>Georgetown</code>'.
+  </li>
+  <li>
+	Keep locations compact.  Use cities or small islands, not countries
+		or regions, so that any future time zone changes do not split
+		locations into different time zones.  E.g. prefer
+		'<code>Paris</code>' to '<code>France</code>', since
+		France has had multiple time zones.
+  </li>
+  <li>
+	Use mainstream English spelling, e.g. prefer
+		'<code>Rome</code>' to '<code>Roma</code>', and prefer
+		'<code>Athens</code>' to the Greek
+		'<code>Αθήνα</code>' or the Romanized
+		'<code>Athína</code>'.
+		The POSIX file name restrictions encourage this rule.
+  </li>
+  <li>
+	Use the most populous among locations in a zone,
+		e.g. prefer '<code>Shanghai</code>' to
+		'<code>Beijing</code>'.  Among locations with
+		similar populations, pick the best-known location,
+		e.g. prefer '<code>Rome</code>' to '<code>Milan</code>'.
+  </li>
+  <li>
+	Use the singular form, e.g. prefer '<code>Canary</code>' to '<code>Canaries</code>'.
+  </li>
+  <li>
+	Omit common suffixes like '<code>_Islands</code>' and
+		'<code>_City</code>', unless that would lead to
+		ambiguity.  E.g. prefer '<code>Cayman</code>' to
+		'<code>Cayman_Islands</code>' and
+		'<code>Guatemala</code>' to
+		'<code>Guatemala_City</code>', but prefer
+		'<code>Mexico_City</code>' to '<code>Mexico</code>'
+		because the country
+		of Mexico has several time zones.
+  </li>
+  <li>
+	Use '<code>_</code>' to represent a space.
+  </li>
+  <li>
+	Omit '<code>.</code>' from abbreviations in names, e.g. prefer
+		'<code>St_Helena</code>' to '<code>St._Helena</code>'.
+  </li>
+  <li>
+	Do not change established names if they only marginally
+		violate the above rules.  For example, don't change
+		the existing name '<code>Rome</code>' to
+		'<code>Milan</code>' merely because
+		Milan's population has grown to be somewhat greater
+		than Rome's.
+  </li>
+  <li>
+	If a name is changed, put its old spelling in the
+		'<code>backward</code>' file.
+		This means old spellings will continue to work.
+  </li>
+</ul>
+
+<p>
+The file '<code>zone1970.tab</code>' lists geographical locations used
+to name time
+zone rules.  It is intended to be an exhaustive list of names for
+geographic regions as described above; this is a subset of the names
+in the data.  Although a '<code>zone1970.tab</code>' location's longitude
+corresponds to its LMT offset with one hour for every 15 degrees east
+longitude, this relationship is not exact.
+</p>
+
+<p>
+Older versions of this package used a different naming scheme,
+and these older names are still supported.
+See the file '<code>backward</code>' for most of these older names
+(e.g., '<code>US/Eastern</code>' instead of '<code>America/New_York</code>').
+The other old-fashioned names still supported are
+'<code>WET</code>', '<code>CET</code>', '<code>MET</code>', and '<code>EET</code>' (see the file '<code>europe</code>').
+</p>
+
+<p>
+Older versions of this package defined legacy names that are
+incompatible with the first rule of location names, but which are
+still supported.  These legacy names are mostly defined in the file
+'<code>etcetera</code>'.  Also, the file '<code>backward</code>' defines the legacy names
+'<code>GMT0</code>', '<code>GMT-0</code>' and '<code>GMT+0</code>', and the file '<code>northamerica</code>' defines the
+legacy names '<code>EST5EDT</code>', '<code>CST6CDT</code>', '<code>MST7MDT</code>', and '<code>PST8PDT</code>'.
+</p>
+
+<p>
+Excluding '<code>backward</code>' should not affect the other data.  If
+'<code>backward</code>' is excluded, excluding '<code>etcetera</code>' should not affect the
+remaining data.
+</p>
+
+
+  </section>
+  <section>
+    <h2 id="abbreviations">Time zone abbreviations</h2>
+<p>
+When this package is installed, it generates time zone abbreviations
+like '<code>EST</code>' to be compatible with human tradition and POSIX.
+Here are the general rules used for choosing time zone abbreviations,
+in decreasing order of importance:
+<ul>
+  <li>
+	Use three or more characters that are ASCII alphanumerics or
+		'<code>+</code>' or '<code>-</code>'.
+		Previous editions of this database also used characters like
+		'<code> </code>' and '<code>?</code>', but these
+		characters have a special meaning to
+		the shell and cause commands like
+			'<code>set `date`</code>'
+		to have unexpected effects.
+		Previous editions of this rule required upper-case letters,
+		but the Congressman who introduced Chamorro Standard Time
+		preferred "ChST", so lower-case letters are now allowed.
+		Also, POSIX from 2001 on relaxed the rule to allow
+		'<code>-</code>', '<code>+</code>',
+		and alphanumeric characters from the portable character set
+		in the current locale.  In practice ASCII alphanumerics and
+		'<code>+</code>' and '<code>-</code>' are safe in all locales.
+
+		In other words, in the C locale the POSIX extended regular
+		expression <code>[-+[:alnum:]]{3,}</code> should match
+		the abbreviation.
+		This guarantees that all abbreviations could have been
+		specified by a POSIX TZ string.
+  </li>
+  <li>
+	Use abbreviations that are in common use among English-speakers,
+		e.g. 'EST' for Eastern Standard Time in North America.
+		We assume that applications translate them to other languages
+		as part of the normal localization process; for example,
+		a French application might translate 'EST' to 'HNE'.
+  </li>
+  <li>
+	For zones whose times are taken from a city's longitude, use the
+		traditional <var>x</var>MT notation, e.g. 'PMT' for
+		Paris Mean Time.
+		The only name like this in current use is 'GMT'.
+  </li>
+  <li>
+	Use 'LMT' for local mean time of locations before the introduction
+		of standard time; see "<a href="#scope">Scope of the
+		tz database</a>".
+  </li>
+  <li>
+	If there is no common English abbreviation, use numeric offsets like
+		<code>-</code>05 and <code>+</code>0830 that are
+		generated by zic's <code>%z</code> notation.
+  </li>
+  <li>
+	Use current abbreviations for older timestamps to avoid confusion.
+		For example, in 1910 a common English abbreviation for UT +01
+		in central Europe was 'MEZ' (short for both "Middle European
+		Zone" and for "Mitteleuropäische Zeit" in German).  Nowadays
+		'CET' ("Central European Time") is more common in English, and
+		the database uses 'CET' even for circa-1910 timestamps as this
+		is less confusing for modern users and avoids the need for
+		determining when 'CET' supplanted 'MEZ' in common usage.
+  </li>
+  <li>
+	Use a consistent style in a zone's history.  For example, if a zone's
+		history tends to use numeric abbreviations and a particular
+		entry could go either way, use a numeric abbreviation.
+  </li>
+</ul>
+    [The remaining guidelines predate the introduction of <code>%z</code>.
+    They are problematic as they mean tz data entries invent
+    notation rather than record it.  These guidelines are now
+    deprecated and the plan is to gradually move to <code>%z</code> for
+    inhabited locations and to "<code>-</code>00" for uninhabited locations.]
+<ul>
+  <li>
+	If there is no common English abbreviation, abbreviate the English
+		translation of the usual phrase used by native speakers.
+		If this is not available or is a phrase mentioning the country
+		(e.g. "Cape Verde Time"), then:
+	<ul>
+	  <li>
+		When a country is identified with a single or principal zone,
+			append 'T' to the country's ISO	code, e.g. 'CVT' for
+			Cape Verde Time.  For summer time append 'ST';
+			for double summer time append 'DST'; etc.
+	  </li>
+	  <li>
+		Otherwise, take the first three letters of an English place
+			name identifying each zone and append 'T', 'ST', etc.
+			as before; e.g. 'CHAST' for CHAtham Summer Time.
+	  </li>
+	</ul>
+  </li>
+  <li>
+	Use UT (with time zone abbreviation '<code>-</code>00') for
+		locations while uninhabited.  The leading
+		'<code>-</code>' is a flag that the time
+		zone is in some sense undefined; this notation is
+		derived from Internet RFC 3339.
+  </li>
+</ul>
+<p>
+Application writers should note that these abbreviations are ambiguous
+in practice: e.g. 'CST' has a different meaning in China than
+it does in the United States.  In new applications, it's often better
+to use numeric UT offsets like '<code>-</code>0600' instead of time zone
+abbreviations like 'CST'; this avoids the ambiguity.
+</p>
+  </section>
+
+
+  <section>
+    <h2 id="accuracy">Accuracy of the tz database</h2>
+<p>
+The tz database is not authoritative, and it surely has errors.
+Corrections are welcome and encouraged; see the file CONTRIBUTING.
+Users requiring authoritative data should consult national standards
+bodies and the references cited in the database's comments.
+</p>
+
+<p>
+Errors in the tz database arise from many sources:
+</p>
+<ul>
+  <li>
+   The tz database predicts future timestamps, and current predictions
+   will be incorrect after future governments change the rules.
+   For example, if today someone schedules a meeting for 13:00 next
+   October 1, Casablanca time, and tomorrow Morocco changes its
+   daylight saving rules, software can mess up after the rule change
+   if it blithely relies on conversions made before the change.
+  </li>
+  <li>
+   The pre-1970 entries in this database cover only a tiny sliver of how
+   clocks actually behaved; the vast majority of the necessary
+   information was lost or never recorded.  Thousands more zones would
+   be needed if the tz database's scope were extended to cover even
+   just the known or guessed history of standard time; for example,
+   the current single entry for France would need to split into dozens
+   of entries, perhaps hundreds.  And in most of the world even this
+   approach would be misleading due to widespread disagreement or
+   indifference about what times should be observed.  In her 2015 book
+   <cite>The Global Transformation of Time, 1870-1950</cite>, Vanessa Ogle writes
+   "Outside of Europe and North America there was no system of time
+   zones at all, often not even a stable landscape of mean times,
+   prior to the middle decades of the twentieth century".  See:
+   Timothy Shenk, <a
+   href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanessa-ogle">Booked:
+   A Global History of Time</a>. <cite>Dissent</cite> 2015-12-17.
+  </li>
+  <li>
+   Most of the pre-1970 data entries come from unreliable sources, often
+   astrology books that lack citations and whose compilers evidently
+   invented entries when the true facts were unknown, without
+   reporting which entries were known and which were invented.
+   These books often contradict each other or give implausible entries,
+   and on the rare occasions when they are checked they are
+   typically found to be incorrect.
+  </li>
+  <li>
+   For the UK the tz database relies on years of first-class work done by
+   Joseph Myers and others; see
+   "<a href="https://www.polyomino.org.uk/british-time/">History of
+   legal time in Britain</a>".
+   Other countries are not done nearly as well.
+  </li>
+  <li>
+   Sometimes, different people in the same city would maintain clocks
+   that differed significantly.  Railway time was used by railroad
+   companies (which did not always agree with each other),
+   church-clock time was used for birth certificates, etc.
+   Often this was merely common practice, but sometimes it was set by law.
+   For example, from 1891 to 1911 the UT offset in France was legally
+   0:09:21 outside train stations and 0:04:21 inside.
+  </li>
+  <li>
+   Although a named location in the tz database stands for the
+   containing region, its pre-1970 data entries are often accurate for
+   only a small subset of that region.  For example, <code>Europe/London</code>
+   stands for the United Kingdom, but its pre-1847 times are valid
+   only for locations that have London's exact meridian, and its 1847
+   transition to GMT is known to be valid only for the L&amp;NW and the
+   Caledonian railways.
+  </li>
+  <li>
+   The tz database does not record the earliest time for which a zone's
+   data entries are thereafter valid for every location in the region.
+   For example, <code>Europe/London</code> is valid for all locations in its
+   region after GMT was made the standard time, but the date of
+   standardization (1880-08-02) is not in the tz database, other than
+   in commentary.  For many zones the earliest time of validity is
+   unknown.
+  </li>
+  <li>
+   The tz database does not record a region's boundaries, and in many
+   cases the boundaries are not known.  For example, the zone
+   <code>America/Kentucky/Louisville</code> represents a region around
+   the city of
+   Louisville, the boundaries of which are unclear.
+  </li>
+  <li>
+   Changes that are modeled as instantaneous transitions in the tz
+   database were often spread out over hours, days, or even decades.
+  </li>
+  <li>
+   Even if the time is specified by law, locations sometimes
+   deliberately flout the law.
+  </li>
+  <li>
+   Early timekeeping practices, even assuming perfect clocks, were
+   often not specified to the accuracy that the tz database requires.
+  </li>
+  <li>
+   Sometimes historical timekeeping was specified more precisely
+   than what the tz database can handle.  For example, from 1909 to
+   1937 Netherlands clocks were legally UT +00:19:32.13, but the tz
+   database cannot represent the fractional second.
+  </li>
+  <li>
+   Even when all the timestamp transitions recorded by the tz database
+   are correct, the tz rules that generate them may not faithfully
+   reflect the historical rules.  For example, from 1922 until World
+   War II the UK moved clocks forward the day following the third
+   Saturday in April unless that was Easter, in which case it moved
+   clocks forward the previous Sunday.  Because the tz database has no
+   way to specify Easter, these exceptional years are entered as
+   separate tz Rule lines, even though the legal rules did not change.
+  </li>
+  <li>
+   The tz database models pre-standard time using the proleptic Gregorian
+   calendar and local mean time (LMT), but many people used other
+   calendars and other timescales.  For example, the Roman Empire used
+   the Julian calendar, and had 12 varying-length daytime hours with a
+   non-hour-based system at night.
+  </li>
+  <li>
+   Early clocks were less reliable, and data entries do not represent
+   clock error.
+  </li>
+  <li>
+   The tz database assumes Universal Time (UT) as an origin, even
+   though UT is not standardized for older timestamps.  In the tz
+   database commentary, UT denotes a family of time standards that
+   includes Coordinated Universal Time (UTC) along with other variants
+   such as UT1 and GMT, with days starting at midnight.  Although UT
+   equals UTC for modern timestamps, UTC was not defined until 1960,
+   so commentary uses the more-general abbreviation UT for timestamps
+   that might predate 1960.  Since UT, UT1, etc. disagree slightly,
+   and since pre-1972 UTC seconds varied in length, interpretation of
+   older timestamps can be problematic when subsecond accuracy is
+   needed.
+  </li>
+  <li>
+   Civil time was not based on atomic time before 1972, and we don't
+   know the history of earth's rotation accurately enough to map SI
+   seconds to historical solar time to more than about one-hour
+   accuracy.  See: Stephenson FR, Morrison LV, Hohenkerk CY.
+   <a href="http://dx.doi.org/10.1098/rspa.2016.0404">Measurement
+   of the Earth's rotation: 720 BC to AD 2015</a>.
+   <cite>Proc Royal Soc A</cite>. 2016 Dec 7;472:20160404.
+   Also see: Espenak F. <a
+   href="https://eclipse.gsfc.nasa.gov/SEhelp/uncertainty2004.html">Uncertainty
+   in Delta T (ΔT)</a>.
+  </li>
+  <li>
+   The relationship between POSIX time (that is, UTC but ignoring leap
+   seconds) and UTC is not agreed upon after 1972.  Although the POSIX
+   clock officially stops during an inserted leap second, at least one
+   proposed standard has it jumping back a second instead; and in
+   practice POSIX clocks more typically either progress glacially during
+   a leap second, or are slightly slowed while near a leap second.
+  </li>
+  <li>
+   The tz database does not represent how uncertain its information is.
+   Ideally it would contain information about when data entries are
+   incomplete or dicey.  Partial temporal knowledge is a field of
+   active research, though, and it's not clear how to apply it here.
+  </li>
+</ul>
+<p>
+In short, many, perhaps most, of the tz database's pre-1970 and future
+timestamps are either wrong or misleading.  Any attempt to pass the
+tz database off as the definition of time should be unacceptable to
+anybody who cares about the facts.  In particular, the tz database's
+LMT offsets should not be considered meaningful, and should not prompt
+creation of zones merely because two locations differ in LMT or
+transitioned to standard time at different dates.
+</p>
+  </section>
+
+
+  <section>
+    <h2 id="functions">Time and date functions</h2>
+<p>
+The tz code contains time and date functions that are upwards
+compatible with those of POSIX.
+</p>
+
+<p>
+POSIX has the following properties and limitations.
+</p>
+<ul>
+  <li>
+    <p>
+	In POSIX, time display in a process is controlled by the
+	environment variable TZ.  Unfortunately, the POSIX TZ string takes
+	a form that is hard to describe and is error-prone in practice.
+	Also, POSIX TZ strings can't deal with other (for example, Israeli)
+	daylight saving time rules, or situations where more than two
+	time zone abbreviations are used in an area.
+    </p>
+    <p>
+      The POSIX TZ string takes the following form:
+    </p>
+    <p>
+      <var>stdoffset</var>[<var>dst</var>[<var>offset</var>][<code>,</code><var>date</var>[<code>/</code><var>time</var>]<code>,</code><var>date</var>[<code>/</code><var>time</var>]]]
+    </p>
+    <p>
+	where:
+    <dl>
+      <dt><var>std</var> and <var>dst</var></dt><dd>
+		are 3 or more characters specifying the standard
+		and daylight saving time (DST) zone names.
+		Starting with POSIX.1-2001, <var>std</var>
+		and <var>dst</var> may also be
+		in a quoted form like '<code>&lt;UTC+10&gt;</code>'; this allows
+		"<code>+</code>" and "<code>-</code>" in the names.
+      </dd>
+      <dt><var>offset</var></dt><dd>
+		is of the form
+		'<code>[&plusmn;]<var>hh</var>:[<var>mm</var>[:<var>ss</var>]]</code>'
+		and specifies the offset west of UT.  '<var>hh</var>'
+		may be a single digit; 0&le;<var>hh</var>&le;24.
+		The default DST offset is one hour ahead of standard time.
+      </dd>
+      <dt><var>date</var>[<code>/</code><var>time</var>]<code>,</code><var>date</var>[<code>/</code><var>time</var>]</dt><dd>
+		specifies the beginning and end of DST.  If this is absent,
+		the system supplies its own rules for DST, and these can
+		differ from year to year; typically US DST rules are used.
+      </dd>
+      <dt><var>time</var></dt><dd>
+		takes the form
+		'<var>hh</var><code>:</code>[<var>mm</var>[<code>:</code><var>ss</var>]]'
+		and defaults to 02:00.
+		This is the same format as the offset, except that a
+		leading '<code>+</code>' or '<code>-</code>' is not allowed.
+      </dd>
+      <dt><var>date</var></dt><dd>
+		takes one of the following forms:
+	<dl>
+	  <dt>J<var>n</var> (1&le;<var>n</var>&le;365)</dt><dd>
+			origin-1 day number not counting February 29
+          </dd>
+	  <dt><var>n</var> (0&le;<var>n</var>&le;365)</dt><dd>
+			origin-0 day number counting February 29 if present
+          </dd>
+	  <dt><code>M</code><var>m</var><code>.</code><var>n</var><code>.</code><var>d</var> (0[Sunday]&le;<var>d</var>&le;6[Saturday], 1&le;<var>n</var>&le;5, 1&le;<var>m</var>&le;12)</dt><dd>
+			for the <var>d</var>th day of
+			week <var>n</var> of month <var>m</var> of the
+			year, where week 1 is the first week in which
+			day <var>d</var> appears, and '<code>5</code>'
+			stands for the last week in which
+			day <var>d</var> appears
+			(which may be either the 4th or 5th week).
+			Typically, this is the only useful form;
+			the <var>n</var>
+			and <code>J</code><var>n</var> forms are
+			rarely used.
+	  </dd>
+</dl>
+</dd>
+</dl>
+	Here is an example POSIX TZ string for New Zealand after 2007.
+	It says that standard time (NZST) is 12 hours ahead of UTC,
+	and that daylight saving time (NZDT) is observed from September's
+	last Sunday at 02:00 until April's first Sunday at 03:00:
+
+        <pre><code>TZ='NZST-12NZDT,M9.5.0,M4.1.0/3'</code></pre>
+
+	This POSIX TZ string is hard to remember, and mishandles some
+	timestamps before 2008.  With this package you can use this
+	instead:
+
+	<pre><code>TZ='Pacific/Auckland'</code></pre>
+  </li>
+  <li>
+	POSIX does not define the exact meaning of TZ values like
+	"<code>EST5EDT</code>".
+	Typically the current US DST rules are used to interpret such values,
+	but this means that the US DST rules are compiled into each program
+	that does time conversion.  This means that when US time conversion
+	rules change (as in the United States in 1987), all programs that
+	do time conversion must be recompiled to ensure proper results.
+  </li>
+  <li>
+	The TZ environment variable is process-global, which makes it hard
+	to write efficient, thread-safe applications that need access
+	to multiple time zones.
+  </li>
+  <li>
+	In POSIX, there's no tamper-proof way for a process to learn the
+	system's best idea of local wall clock.  (This is important for
+	applications that an administrator wants used only at certain
+	times &ndash;
+	without regard to whether the user has fiddled the TZ environment
+	variable.  While an administrator can "do everything in UTC" to get
+	around the problem, doing so is inconvenient and precludes handling
+	daylight saving time shifts - as might be required to limit phone
+	calls to off-peak hours.)
+  </li>
+  <li>
+	POSIX provides no convenient and efficient way to determine the UT
+	offset and time zone abbreviation of arbitrary timestamps,
+	particularly for time zone settings that do not fit into the
+	POSIX model.
+  </li>
+  <li>
+	POSIX requires that systems ignore leap seconds.
+  </li>
+  <li>
+	The tz code attempts to support all the <code>time_t</code>
+	implementations allowed by POSIX.  The <code>time_t</code>
+	type represents a nonnegative count of
+	seconds since 1970-01-01 00:00:00 UTC, ignoring leap seconds.
+	In practice, <code>time_t</code> is usually a signed 64- or
+	32-bit integer; 32-bit signed <code>time_t</code> values stop
+	working after 2038-01-19 03:14:07 UTC, so
+	new implementations these days typically use a signed 64-bit integer.
+	Unsigned 32-bit integers are used on one or two platforms,
+	and 36-bit and 40-bit integers are also used occasionally.
+	Although earlier POSIX versions allowed <code>time_t</code> to be a
+	floating-point type, this was not supported by any practical
+	systems, and POSIX.1-2013 and the tz code both
+	require <code>time_t</code>
+	to be an integer type.
+  </li>
+</ul>
+<p>
+These are the extensions that have been made to the POSIX functions:
+</p>
+<ul>
+  <li>
+    <p>
+	The TZ environment variable is used in generating the name of a file
+	from which time zone information is read (or is interpreted a la
+	POSIX); TZ is no longer constrained to be a three-letter time zone
+	name followed by a number of hours and an optional three-letter
+	daylight time zone name.  The daylight saving time rules to be used
+	for a particular time zone are encoded in the time zone file;
+	the format of the file allows U.S., Australian, and other rules to be
+	encoded, and allows for situations where more than two time zone
+	abbreviations are used.
+    </p>
+    <p>
+	It was recognized that allowing the TZ environment variable to
+	take on values such as '<code>America/New_York</code>' might
+	cause "old" programs
+	(that expect TZ to have a certain form) to operate incorrectly;
+	consideration was given to using some other environment variable
+	(for example, TIMEZONE) to hold the string used to generate the
+	time zone information file name.  In the end, however, it was decided
+	to continue using TZ: it is widely used for time zone purposes;
+	separately maintaining both TZ and TIMEZONE seemed a nuisance;
+	and systems where "new" forms of TZ might cause problems can simply
+	use TZ values such as "<code>EST5EDT</code>" which can be used both by
+	"new" programs (a la POSIX) and "old" programs (as zone names and
+	offsets).
+    </p>
+</li>
+<li>
+	The code supports platforms with a UT offset member
+	in <code>struct tm</code>,
+	e.g., <code>tm_gmtoff</code>.
+</li>
+<li>
+	The code supports platforms with a time zone abbreviation member in
+	<code>struct tm</code>, e.g., <code>tm_zone</code>.
+</li>
+<li>
+	Since the TZ environment variable can now be used to control time
+	conversion, the <code>daylight</code>
+	and <code>timezone</code> variables are no longer needed.
+	(These variables are defined and set by <code>tzset</code>;
+	however, their values will not be used
+	by <code>localtime</code>.)
+</li>
+<li>
+	Functions <code>tzalloc</code>, <code>tzfree</code>,
+	<code>localtime_rz</code>, and <code>mktime_z</code> for
+	more-efficient thread-safe applications that need to use
+	multiple time zones.  The <code>tzalloc</code>
+	and <code>tzfree</code> functions allocate and free objects of
+	type <code>timezone_t</code>, and <code>localtime_rz</code>
+	and <code>mktime_z</code> are like <code>localtime_r</code>
+	and <code>mktime</code> with an extra
+	<code>timezone_t</code> argument.  The functions were inspired
+	by NetBSD.
+</li>
+<li>
+	A function <code>tzsetwall</code> has been added to arrange
+	for the system's
+	best approximation to local wall clock time to be delivered by
+	subsequent calls to <code>localtime</code>.  Source code for portable
+	applications that "must" run on local wall clock time should call
+	<code>tzsetwall</code>; if such code is moved to "old" systems that don't
+	provide tzsetwall, you won't be able to generate an executable program.
+	(These time zone functions also arrange for local wall clock time to be
+	used if tzset is called &ndash; directly or indirectly &ndash;
+	and there's no TZ
+	environment variable; portable applications should not, however, rely
+	on this behavior since it's not the way SVR2 systems behave.)
+</li>
+<li>
+	Negative <code>time_t</code> values are supported, on systems
+	where <code>time_t</code> is signed.
+</li>
+<li>
+	These functions can account for leap seconds, thanks to Bradley White.
+</li>
+</ul>
+<p>
+Points of interest to folks with other systems:
+</p>
+<ul>
+  <li>
+	Code compatible with this package is already part of many platforms,
+	including GNU/Linux, Android, the BSDs, Chromium OS, Cygwin, AIX, iOS,
+	BlackBery 10, macOS, Microsoft Windows, OpenVMS, and Solaris.
+	On such hosts, the primary use of this package
+	is to update obsolete time zone rule tables.
+	To do this, you may need to compile the time zone compiler
+	'<code>zic</code>' supplied with this package instead of using
+	the system '<code>zic</code>', since the format
+	of <code>zic</code>'s input is occasionally extended, and a
+	platform may still be shipping an older <code>zic</code>.
+  </li>
+  <li>
+	The UNIX Version 7 <code>timezone</code> function is not
+	present in this package;
+	it's impossible to reliably map timezone's arguments (a "minutes west
+	of GMT" value and a "daylight saving time in effect" flag) to a
+	time zone abbreviation, and we refuse to guess.
+	Programs that in the past used the timezone function may now examine
+	<code>localtime(&amp;clock)-&gt;tm_zone</code>
+	(if <code>TM_ZONE</code> is defined) or
+	<code>tzname[localtime(&amp;clock)-&gt;tm_isdst]</code>
+	(if <code>HAVE_TZNAME</code> is defined)
+	to learn the correct time zone abbreviation to use.
+  </li>
+  <li>
+	The 4.2BSD <code>gettimeofday</code> function is not used in
+	this package.
+	This formerly let users obtain the current UTC offset and DST flag,
+	but this functionality was removed in later versions of BSD.
+  </li>
+  <li>
+	In SVR2, time conversion fails for near-minimum or near-maximum
+	<code>time_t</code> values when doing conversions for places
+	that don't use UT.
+	This package takes care to do these conversions correctly.
+	A comment in the source code tells how to get compatibly wrong
+	results.
+  </li>
+</ul>
+<p>
+The functions that are conditionally compiled
+if <code>STD_INSPIRED</code> is defined
+should, at this point, be looked on primarily as food for thought.  They are
+not in any sense "standard compatible" &ndash; some are not, in fact,
+specified in <em>any</em> standard.  They do, however, represent responses of
+various authors to
+standardization proposals.
+</p>
+
+<p>
+Other time conversion proposals, in particular the one developed by folks at
+Hewlett Packard, offer a wider selection of functions that provide capabilities
+beyond those provided here.  The absence of such functions from this package
+is not meant to discourage the development, standardization, or use of such
+functions.  Rather, their absence reflects the decision to make this package
+contain valid extensions to POSIX, to ensure its broad acceptability.  If
+more powerful time conversion functions can be standardized, so much the
+better.
+</p>
+  </section>
+
+
+  <section>
+    <h2 id="stability">Interface stability</h2>
+<p>
+The tz code and data supply the following interfaces:
+</p>
+<ul>
+  <li>
+   A set of zone names as per "<a href="#naming">Names of time zone
+   rules</a>" above.
+  </li>
+  <li>
+   Library functions described in "<a href="#functions">Time and date
+   functions</a>" above.
+  </li>
+  <li>
+   The programs <code>tzselect</code>, <code>zdump</code>,
+   and <code>zic</code>, documented in their man pages.
+  </li>
+  <li>
+   The format of <code>zic</code> input files, documented in
+   the <code>zic</code> man page.
+  </li>
+  <li>
+   The format of <code>zic</code> output files, documented in
+   the <code>tzfile</code> man page.
+  </li>
+  <li>
+   The format of zone table files, documented in <code>zone1970.tab</code>.
+  </li>
+  <li>
+   The format of the country code file, documented in <code>iso3166.tab</code>.
+  </li>
+  <li>
+   The version number of the code and data, as the first line of
+   the text file '<code>version</code>' in each release.
+  </li>
+</ul>
+<p>
+Interface changes in a release attempt to preserve compatibility with
+recent releases.  For example, tz data files typically do not rely on
+recently-added <code>zic</code> features, so that users can run
+older <code>zic</code> versions to process newer data
+files.  <a href="tz-link.htm">Sources for time zone and daylight
+saving time data</a> describes how
+releases are tagged and distributed.
+</p>
+
+<p>
+Interfaces not listed above are less stable.  For example, users
+should not rely on particular UT offsets or abbreviations for
+timestamps, as data entries are often based on guesswork and these
+guesses may be corrected or improved.
+</p>
+  </section>
+
+
+  <section>
+    <h2 id="calendar">Calendrical issues</h2>
+<p>
+Calendrical issues are a bit out of scope for a time zone database,
+but they indicate the sort of problems that we would run into if we
+extended the time zone database further into the past.  An excellent
+resource in this area is Nachum Dershowitz and Edward M. Reingold,
+<cite><a href="https://www.cs.tau.ac.il/~nachum/calendar-book/third-edition/">Calendrical
+Calculations: Third Edition</a></cite>, Cambridge University Press (2008).
+Other information and sources are given in the file '<samp>calendars</samp>'
+in the tz distribution.  They sometimes disagree.
+</p>
+  </section>
+
+
+  <section>
+    <h2 id="planets">Time and time zones on other planets</h2>
+<p>
+Some people's work schedules use Mars time.  Jet Propulsion Laboratory
+(JPL) coordinators have kept Mars time on and off at least since 1997
+for the Mars Pathfinder mission.  Some of their family members have
+also adapted to Mars time.  Dozens of special Mars watches were built
+for JPL workers who kept Mars time during the Mars Exploration
+Rovers mission (2004).  These timepieces look like normal Seikos and
+Citizens but use Mars seconds rather than terrestrial seconds.
+</p>
+
+<p>
+A Mars solar day is called a "sol" and has a mean period equal to
+about 24 hours 39 minutes 35.244 seconds in terrestrial time.  It is
+divided into a conventional 24-hour clock, so each Mars second equals
+about 1.02749125 terrestrial seconds.
+</p>
+
+<p>
+The prime meridian of Mars goes through the center of the crater
+Airy-0, named in honor of the British astronomer who built the
+Greenwich telescope that defines Earth's prime meridian.  Mean solar
+time on the Mars prime meridian is called Mars Coordinated Time (MTC).
+</p>
+
+<p>
+Each landed mission on Mars has adopted a different reference for
+solar time keeping, so there is no real standard for Mars time zones.
+For example, the Mars Exploration Rover project (2004) defined two
+time zones "Local Solar Time A" and "Local Solar Time B" for its two
+missions, each zone designed so that its time equals local true solar
+time at approximately the middle of the nominal mission.  Such a "time
+zone" is not particularly suited for any application other than the
+mission itself.
+</p>
+
+<p>
+Many calendars have been proposed for Mars, but none have achieved
+wide acceptance.  Astronomers often use Mars Sol Date (MSD) which is a
+sequential count of Mars solar days elapsed since about 1873-12-29
+12:00 GMT.
+</p>
+
+<p>
+In our solar system, Mars is the planet with time and calendar most
+like Earth's.  On other planets, Sun-based time and calendars would
+work quite differently.  For example, although Mercury's sidereal
+rotation period is 58.646 Earth days, Mercury revolves around the Sun
+so rapidly that an observer on Mercury's equator would see a sunrise
+only every 175.97 Earth days, i.e., a Mercury year is 0.5 of a Mercury
+day.  Venus is more complicated, partly because its rotation is
+slightly retrograde: its year is 1.92 of its days.  Gas giants like
+Jupiter are trickier still, as their polar and equatorial regions
+rotate at different rates, so that the length of a day depends on
+latitude.  This effect is most pronounced on Neptune, where the day is
+about 12 hours at the poles and 18 hours at the equator.
+</p>
+
+<p>
+Although the tz database does not support time on other planets, it is
+documented here in the hopes that support will be added eventually.
+</p>
+
+<p>
+Sources:
+</p>
+<ul>
+  <li>
+Michael Allison and Robert Schmunk,
+"<a href="https://www.giss.nasa.gov/tools/mars24/help/notes.html">Technical
+Notes on Mars Solar Time as Adopted by the Mars24 Sunclock</a>"
+(2012-08-08).
+  </li>
+  <li>
+Jia-Rui Chong,
+"<a href="http://articles.latimes.com/2004/jan/14/science/sci-marstime14">Workdays
+Fit for a Martian</a>", Los Angeles Times
+(2004-01-14), pp A1, A20-A21.
+  </li>
+  <li>
+Tom Chmielewski,
+"<a href="https://www.theatlantic.com/technology/archive/2015/02/jet-lag-is-worse-on-mars/386033/">Jet
+Lag Is Worse on Mars</a>", The Atlantic (2015-02-26)
+  </li>
+  <li>
+Matt Williams,
+"<a href="https://www.universetoday.com/37481/days-of-the-planets/">How
+long is a day on the other planets of the solar system?</a>"
+(2017-04-27).
+  </li>
+</ul>
+  </section>
+
+  <footer>
+    <hr>
+This file is in the public domain, so clarified as of 2009-05-17 by
+Arthur David Olson.
+  </footer>
+</body>
+</html>
+native
\ No newline at end of property
+FreeBSD=%H
\ No newline at end of property
+text/html
\ No newline at end of property
--- contrib/tzdata/version.orig
+++ contrib/tzdata/version
@@ -1 +1 @@
-2016i
+2017c
--- contrib/tzdata/zishrink.awk.orig
+++ contrib/tzdata/zishrink.awk
@@ -0,0 +1,156 @@
+# Convert tzdata source into a smaller version of itself.
+
+# Contributed by Paul Eggert.  This file is in the public domain.
+
+# This is not a general-purpose converter; it is designed for current tzdata.
+# 'zic' should treat this script's output as if it were identical to
+# this script's input.
+
+
+# Return a new rule name.
+# N_RULE_NAMES keeps track of how many rule names have been generated.
+
+function gen_rule_name(alphabet, base, rule_name, n, digit)
+{
+  alphabet = ""
+  alphabet = alphabet "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+  alphabet = alphabet "abcdefghijklmnopqrstuvwxyz"
+  alphabet = alphabet "!$%&'()*+,./:;<=>?@[\\]^_`{|}~"
+  base = length(alphabet)
+  rule_name = ""
+  n = n_rule_names++
+
+  do {
+    n -= rule_name && n <= base
+    digit = n % base
+    rule_name = substr(alphabet, digit + 1, 1) rule_name
+    n = (n - digit) / base
+  } while (n);
+
+  return rule_name
+}
+
+# Process an input line and save it for later output.
+
+function process_input_line(line, field, end, i, n, startdef)
+{
+  # Remove comments, normalize spaces, and append a space to each line.
+  sub(/#.*/, "", line)
+  line = line " "
+  gsub(/[[:space:]]+/, " ", line)
+
+  # Abbreviate keywords.  Do not abbreviate "Link" to just "L",
+  # as pre-2017c zic erroneously diagnoses "Li" as ambiguous.
+  sub(/^Link /, "Li ", line)
+  sub(/^Rule /, "R ", line)
+  sub(/^Zone /, "Z ", line)
+
+  # SystemV rules are not needed.
+  if (line ~ /^R SystemV /) return
+
+  # Replace FooAsia rules with the same rules without "Asia", as they
+  # are duplicates.
+  if (match(line, /[^ ]Asia /)) {
+    if (line ~ /^R /) return
+    line = substr(line, 1, RSTART) substr(line, RSTART + 5)
+  }
+
+  # Abbreviate times.
+  while (match(line, /[: ]0+[0-9]/))
+    line = substr(line, 1, RSTART) substr(line, RSTART + RLENGTH - 1)
+  while (match(line, /:0[^:]/))
+    line = substr(line, 1, RSTART - 1) substr(line, RSTART + 2)
+
+  # Abbreviate weekday names.  Do not abbreviate "Sun" and "Sat", as
+  # pre-2017c zic erroneously diagnoses "Su" and "Sa" as ambiguous.
+  while (match(line, / (last)?(Mon|Wed|Fri)[ <>]/)) {
+    end = RSTART + RLENGTH
+    line = substr(line, 1, end - 4) substr(line, end - 1)
+  }
+  while (match(line, / (last)?(Tue|Thu)[ <>]/)) {
+    end = RSTART + RLENGTH
+    line = substr(line, 1, end - 3) substr(line, end - 1)
+  }
+
+  # Abbreviate "max", "only" and month names.
+  # Do not abbreviate "min", as pre-2017c zic erroneously diagnoses "mi"
+  # as ambiguous.
+  gsub(/ max /, " ma ", line)
+  gsub(/ only /, " o ", line)
+  gsub(/ Jan /, " Ja ", line)
+  gsub(/ Feb /, " F ", line)
+  gsub(/ Apr /, " Ap ", line)
+  gsub(/ Aug /, " Au ", line)
+  gsub(/ Sep /, " S ", line)
+  gsub(/ Oct /, " O ", line)
+  gsub(/ Nov /, " N ", line)
+  gsub(/ Dec /, " D ", line)
+
+  # Strip leading and trailing space.
+  sub(/^ /, "", line)
+  sub(/ $/, "", line)
+
+  # Remove unnecessary trailing zero fields.
+  sub(/ 0+$/, "", line)
+
+  # Remove unnecessary trailing days-of-month "1".
+  if (match(line, /[[:alpha:]] 1$/))
+    line = substr(line, 1, RSTART)
+
+  # Remove unnecessary trailing " Ja" (for January).
+  sub(/ Ja$/, "", line)
+
+  n = split(line, field)
+
+  # Abbreviate rule names.
+  i = field[1] == "Z" ? 4 : field[1] == "Li" ? 0 : 2
+  if (i && field[i] ~ /^[^-+0-9]/) {
+    if (!rule[field[i]])
+      rule[field[i]] = gen_rule_name()
+    field[i] = rule[field[i]]
+  }
+
+  # If this zone supersedes an earlier one, delete the earlier one
+  # from the saved output lines.
+  startdef = ""
+  if (field[1] == "Z")
+    zonename = startdef = field[2]
+  else if (field[1] == "Li")
+    zonename = startdef = field[3]
+  else if (field[1] == "R")
+    zonename = ""
+  if (startdef) {
+    i = zonedef[startdef]
+    if (i) {
+      do
+	output_line[i - 1] = ""
+      while (output_line[i++] ~ /^[-+0-9]/);
+    }
+  }
+  zonedef[zonename] = nout + 1
+
+  # Save the line for later output.
+  line = field[1]
+  for (i = 2; i <= n; i++)
+    line = line " " field[i]
+  output_line[nout++] = line
+}
+
+function output_saved_lines(i)
+{
+  for (i = 0; i < nout; i++)
+    if (output_line[i])
+      print output_line[i]
+}
+
+BEGIN {
+  print "# This zic input file is in the public domain."
+}
+
+/^[[:space:]]*[^#[:space:]]/ {
+  process_input_line($0)
+}
+
+END {
+  output_saved_lines()
+}
+native
\ No newline at end of property
+FreeBSD=%H
\ No newline at end of property
+text/plain
\ No newline at end of property
--- contrib/tzdata/zone.tab.orig
+++ contrib/tzdata/zone.tab
@@ -142,6 +142,7 @@
 CI	+0519-00402	Africa/Abidjan
 CK	-2114-15946	Pacific/Rarotonga
 CL	-3327-07040	America/Santiago	Chile (most areas)
+CL	-5309-07055	America/Punta_Arenas	Region of Magallanes
 CL	-2709-10926	Pacific/Easter	Easter Island
 CM	+0403+00942	Africa/Douala
 CN	+3114+12128	Asia/Shanghai	Beijing Time
@@ -185,7 +186,7 @@
 GD	+1203-06145	America/Grenada
 GE	+4143+04449	Asia/Tbilisi
 GF	+0456-05220	America/Cayenne
-GG	+4927-00232	Europe/Guernsey
+GG	+492717-0023210	Europe/Guernsey
 GH	+0533-00013	Africa/Accra
 GI	+3608-00521	Europe/Gibraltar
 GL	+6411-05144	America/Godthab	Greenland (most areas)
@@ -220,7 +221,7 @@
 IR	+3540+05126	Asia/Tehran
 IS	+6409-02151	Atlantic/Reykjavik
 IT	+4154+01229	Europe/Rome
-JE	+4912-00207	Europe/Jersey
+JE	+491101-0020624	Europe/Jersey
 JM	+175805-0764736	America/Jamaica
 JO	+3157+03556	Asia/Amman
 JP	+353916+1394441	Asia/Tokyo
@@ -239,7 +240,8 @@
 KZ	+4315+07657	Asia/Almaty	Kazakhstan (most areas)
 KZ	+4448+06528	Asia/Qyzylorda	Qyzylorda/Kyzylorda/Kzyl-Orda
 KZ	+5017+05710	Asia/Aqtobe	Aqtobe/Aktobe
-KZ	+4431+05016	Asia/Aqtau	Atyrau/Atirau/Gur'yev, Mangghystau/Mankistau
+KZ	+4431+05016	Asia/Aqtau	Mangghystau/Mankistau
+KZ	+4707+05156	Asia/Atyrau	Atyrau/Atirau/Gur'yev
 KZ	+5113+05121	Asia/Oral	West Kazakhstan
 LA	+1758+10236	Asia/Vientiane
 LB	+3353+03530	Asia/Beirut
@@ -330,14 +332,15 @@
 RU	+5443+02030	Europe/Kaliningrad	MSK-01 - Kaliningrad
 RU	+554521+0373704	Europe/Moscow	MSK+00 - Moscow area
 RU	+4457+03406	Europe/Simferopol	MSK+00 - Crimea
-RU	+4844+04425	Europe/Volgograd	MSK+00 - Volgograd, Saratov
+RU	+4844+04425	Europe/Volgograd	MSK+00 - Volgograd
 RU	+5836+04939	Europe/Kirov	MSK+00 - Kirov
 RU	+4621+04803	Europe/Astrakhan	MSK+01 - Astrakhan
+RU	+5134+04602	Europe/Saratov	MSK+01 - Saratov
+RU	+5420+04824	Europe/Ulyanovsk	MSK+01 - Ulyanovsk
 RU	+5312+05009	Europe/Samara	MSK+01 - Samara, Udmurtia
-RU	+5420+04824	Europe/Ulyanovsk	MSK+01 - Ulyanovsk
 RU	+5651+06036	Asia/Yekaterinburg	MSK+02 - Urals
 RU	+5500+07324	Asia/Omsk	MSK+03 - Omsk
-RU	+5502+08255	Asia/Novosibirsk	MSK+03 - Novosibirsk
+RU	+5502+08255	Asia/Novosibirsk	MSK+04 - Novosibirsk
 RU	+5322+08345	Asia/Barnaul	MSK+04 - Altai
 RU	+5630+08458	Asia/Tomsk	MSK+04 - Tomsk
 RU	+5345+08707	Asia/Novokuznetsk	MSK+04 - Kemerovo
@@ -395,7 +398,6 @@
 UA	+4837+02218	Europe/Uzhgorod	Ruthenia
 UA	+4750+03510	Europe/Zaporozhye	Zaporozh'ye/Zaporizhia; Lugansk/Luhansk (east)
 UG	+0019+03225	Africa/Kampala
-UM	+1645-16931	Pacific/Johnston	Johnston Atoll
 UM	+2813-17722	Pacific/Midway	Midway Islands
 UM	+1917+16637	Pacific/Wake	Wake Island
 US	+404251-0740023	America/New_York	Eastern (most areas)
--- contrib/tzdata/zone1970.tab.orig
+++ contrib/tzdata/zone1970.tab
@@ -2,7 +2,7 @@
 #
 # This file is in the public domain.
 #
-# From Paul Eggert (2014-07-31):
+# From Paul Eggert (2017-10-01):
 # This file contains a table where each row stands for a zone where
 # civil time stamps have agreed since 1970.  Columns are separated by
 # a single tab.  Lines beginning with '#' are comments.  All text uses
@@ -16,7 +16,7 @@
 #     either +-DDMM+-DDDMM or +-DDMMSS+-DDDMMSS,
 #     first latitude (+ is north), then longitude (+ is east).
 # 3.  Zone name used in value of TZ environment variable.
-#     Please see the 'Theory' file for how zone names are chosen.
+#     Please see the theory.html file for how zone names are chosen.
 #     If multiple zones overlap a country, each has a row in the
 #     table, with each column 1 containing the country code.
 # 4.  Comments; present if and only if a country has multiple zones.
@@ -136,6 +136,7 @@
 CI,BF,GM,GN,ML,MR,SH,SL,SN,ST,TG	+0519-00402	Africa/Abidjan
 CK	-2114-15946	Pacific/Rarotonga
 CL	-3327-07040	America/Santiago	Chile (most areas)
+CL	-5309-07055	America/Punta_Arenas	Region of Magallanes
 CL	-2709-10926	Pacific/Easter	Easter Island
 CN	+3114+12128	Asia/Shanghai	Beijing Time
 CN	+4348+08735	Asia/Urumqi	Xinjiang Time
@@ -211,8 +212,9 @@
 KR	+3733+12658	Asia/Seoul
 KZ	+4315+07657	Asia/Almaty	Kazakhstan (most areas)
 KZ	+4448+06528	Asia/Qyzylorda	Qyzylorda/Kyzylorda/Kzyl-Orda
-KZ	+5017+05710	Asia/Aqtobe	Aqtobe/Aktobe
-KZ	+4431+05016	Asia/Aqtau	Atyrau/Atirau/Gur'yev, Mangghystau/Mankistau
+KZ	+5017+05710	Asia/Aqtobe	Aqtöbe/Aktobe
+KZ	+4431+05016	Asia/Aqtau	Mangghystaū/Mankistau
+KZ	+4707+05156	Asia/Atyrau	Atyraū/Atirau/Gur'yev
 KZ	+5113+05121	Asia/Oral	West Kazakhstan
 LB	+3353+03530	Asia/Beirut
 LK	+0656+07951	Asia/Colombo
@@ -288,14 +290,15 @@
 RU	+5443+02030	Europe/Kaliningrad	MSK-01 - Kaliningrad
 RU	+554521+0373704	Europe/Moscow	MSK+00 - Moscow area
 RU	+4457+03406	Europe/Simferopol	MSK+00 - Crimea
-RU	+4844+04425	Europe/Volgograd	MSK+00 - Volgograd, Saratov
+RU	+4844+04425	Europe/Volgograd	MSK+00 - Volgograd
 RU	+5836+04939	Europe/Kirov	MSK+00 - Kirov
 RU	+4621+04803	Europe/Astrakhan	MSK+01 - Astrakhan
+RU	+5134+04602	Europe/Saratov	MSK+01 - Saratov
+RU	+5420+04824	Europe/Ulyanovsk	MSK+01 - Ulyanovsk
 RU	+5312+05009	Europe/Samara	MSK+01 - Samara, Udmurtia
-RU	+5420+04824	Europe/Ulyanovsk	MSK+01 - Ulyanovsk
 RU	+5651+06036	Asia/Yekaterinburg	MSK+02 - Urals
 RU	+5500+07324	Asia/Omsk	MSK+03 - Omsk
-RU	+5502+08255	Asia/Novosibirsk	MSK+03 - Novosibirsk
+RU	+5502+08255	Asia/Novosibirsk	MSK+04 - Novosibirsk
 RU	+5322+08345	Asia/Barnaul	MSK+04 - Altai
 RU	+5630+08458	Asia/Tomsk	MSK+04 - Tomsk
 RU	+5345+08707	Asia/Novokuznetsk	MSK+04 - Kemerovo
@@ -314,10 +317,11 @@
 SA,KW,YE	+2438+04643	Asia/Riyadh
 SB	-0932+16012	Pacific/Guadalcanal
 SC	-0440+05528	Indian/Mahe
-SD,SS	+1536+03232	Africa/Khartoum
+SD	+1536+03232	Africa/Khartoum
 SE	+5920+01803	Europe/Stockholm
 SG	+0117+10351	Asia/Singapore
 SR	+0550-05510	America/Paramaribo
+SS	+0451+03137	Africa/Juba
 SV	+1342-08912	America/El_Salvador
 SY	+3330+03618	Asia/Damascus
 TC	+2128-07108	America/Grand_Turk
